Posts Tagged ‘food intolerance’

The simplest and most certain test for any sensitivity reaction is to expose the person concerned to the substance under suspicion and see what happens. This is known as a

challenge test. With true allergies, challenge tests are powerful tools, but they are also alarmingly close to reality. The risk of provoking a severe reaction requires a very

cautious approach.
By comparison, an indirect test – a roundabout way of seeing how the body responds, such as the skin-prick test (see p. 91) – has the advantage of rarely producing dangerous

reactions. The downside is that indirect tests can be misleading, precisely because they are not like the real-life situation. No indirect test is perfect – there are always

false positives and false negatives (see box on p. 91).
Challenge tests
If you undergo a challenge test with food or an airborne allergen, you will also be given dummy challenges with an innocuous substance which is indistinguishable from the item

being tested. Neither you, nor the tester who is scoring the reaction, should know which is which. This is called a double-blind trial because, to eliminate all possible bias,

both of you are in the dark. (The full name is a ‘double-blind placebo-controlled trial’ – the dummy challenge is also called a ‘placebo challenge’ or ‘control challenge’.)
The double-blind trial is a standard medical procedure and does not imply that the doctors think you are faking symptoms. Psychological forces are powerful things, and just

thinking that you might react to a test can be enough to produce a reaction – the process that generates the symptoms is largely unconscious.
Food challenge
A food challenge – eating the food that is under suspicion – is a key test for food intolerance (see p. 197). It is sometimes used for food allergy and other forms of food

sensitivity too, as a follow-up to skin tests. Some allergists use a food challenge only if the skin test is at odds with actual events reported by the patient. Other allergists

use food challenge more readily, to confirm skin-test results, and to assess the severity of the reaction.
Extreme caution must be exercised with immediate food allergy, because of the considerable risks involved. The test must be done under medical supervision with resuscitation

equipment to hand. A challenge test should never be done for true food allergy without some careful preliminary tests on the face and the lips (see box on p. 23). Even if these

tests produce no reaction, only tiny amounts of the food should be eaten to begin with.
Bronchial challenge
This type of test involves inhalation of an airborne allergen – such as pollen – suspected of causing asthma. Bronchial challenge carries the risk of provoking a severe asthma

attack, and few doctors use it unless there are compelling reasons to do so – such as demonstrating that someone’s asthma is due to an allergen encountered at work.
Skin-prick tests
This is an indirect method of detecting true allergic reactions. It is one of a family of skin tests that use a similar approach. The three different tests in this family are

known as: skin-prick tests or prick tests, puncture tests, and scratch tests.
For the skin-prick test – the technique used in Britain – a small drop of liquid containing an allergen, such as grass pollen, is placed on the arm. The doctor makes a small

prick in the skin, under the drop of liquid, allowing a minuscule amount of the allergen to get into the skin. A positive reaction is recorded if a red bump develops soon

afterwards. For accuracy, the bump must be compared to positive and negative controls (see below).
The puncture method is very similar to the skin-prick test but uses a slightly different technique for breaking the skin. The term prick-puncture test covers both techniques.
With the scratch method, the skin is scratched lightly, and the allergen solution is then applied over the scratch. This method gives less consistent results than prick-puncture

testing.
It is important to include a negative control in the test – a skin-prick test with plain salt water (saline). This should not produce much of a bump – if it does, the skin is

clearly over-reactive and the tests more difficult to assess. The doctor should also include a positive control – a skin-prick test with histamine, the substance that plays a

central role in allergic reactions. This should always produce a bump. If it does not, the skin is decidedly under-reactive, and the tests are invalid.
Taking antihistamines will make the skin under-reactive, and you should stop taking them before the testing, for a period ranging from a day to several weeks – it varies

depending on the particular antihistamine. Ask your doctor for specific instructions about stopping these and other drugs before testing.
Skin tends to be over-reactive to testing in people with dermatographism (see p. 52). Blood tests for specific IgE,
such as RASTs (see p. 92), are needed for anyone who has this condition. Eczema sufferers with a rash over large areas of the body may also require blood tests, if there is too

little clear skin for testing.
Skin-prick tests can produce both false positives and false negatives (see box below). Some allergic diseases will give a lot of false negatives and relatively few false

positives, while for others the reverse is true. The allergen itself influences the rates of misleading reactions: for example, tests for soya allergy are notoriously

unreliable, whereas those for peanut are far more accurate. The age of the person being tested also makes a difference. With all these influences at work, interpreting the test

responses is a real art, and the doctor’s experience counts for a lot.
All sorts of people offer skin-prick tests, including alternative practitioners. Get them done by a qualified doctor, preferably by an allergist, who will know how to make sense

of the reactions.
Note that the purpose of these tests, and of blood tests for specific IgE, is to identify the allergens that are bringing on your symptoms, not to predict how strongly you will

react to those allergens. The tests may give some Indication of the intensity of your reaction, but they cannot be regarded as a good guide to how you will respond to the

allergen in the future.
The safety record of skin-prick tests is very good. Occasionally a systemic reaction (anaphylaxis) occurs with these tests, but there are no records of any deaths. Nevertheless,

if you suffer from severe asthma or have experienced anaphylactic shock in the past, it is advisable for the doctor to have adrenaline and resuscitation equipment available.

Those with strong allergic reactions to latex may also react badly if they are tested with an allergen that cross-reacts with latex (e.g. cypress pollen), not just when tested

with latex itself. Taking beta-Mockers (see box on p. 150) increases the risk of a life-threatening reaction for anyone in these higher-risk categories.
False positives and false negatives
Apart from challenge tests, none of the tests used for allergy works with 100% accuracy. Most give both false positives and false negatives.
A false positive means that there is a positive test but no actual reaction when the allergen is encountered (e.g. eaten or inhaled). A false negative means that there is a

negative test result despite a genuine reaction (as shown by a challenge test, for example).
A test that gives relatively few false positives has good positive predictive value – in other words, if it suggests you are allergic to something, you probably are.
A test that gives relatively few false negatives has good negative predictive value. If it comes up negative, you are probably not allergic to that allergen.
Some tests for allergic reactions show good positive predictive value but poor negative predictive value, while for other tests the reverse is true.

Investigating Food Intolerance

COLICKY BABIES
If you have followed the measures described on pp. 78-9 but have had little or no success in reducing colic symptoms so far, it makes sense to look into the possibility of a food sensitivity reaction (either intolerance or a mild allergy) to food proteins. This is a very different problem from lactose intolerance (an inability to digest the milk sugar, called lactose, due to a shortage of lactase - see p. 79), although the two can get entangled, creating a complex and confusing set of responses.
The complications arise because, when there is diarrhoea as a result of allergy or intolerance (or from any other cause, including infections) it temporarily strips the gut of its lactose-digesting capacity. This problem is called secondary lactase deficiency, and it will correct itself quite quickly once the real cause of the diarrhoea is eliminated.
Unfortunately, the routine medical tests for lactase deficiency do not distinguish between this temporary problem and the much rarer primary lactase deficiency, which is inherited and life-long.
So if your child has had these routine tests, and you have been told that they show primary lactase deficiency, it remains possible that the real problem is a reaction to milk proteins (or proteins from other foods), and that the lactose intolerance is an effect of this, which adds to the diarrhoea, but is not the root cause of it. If so, eliminating the offending food from the baby’s diet (or the mother’s) will produce impressive results, whereas reducing or eliminating lactose only helps a little.
The purpose of the dietary investigations described here is to discover which foods are causing problems for your baby. In the case of bottle-fed babies, the answer is usually cow’s milk – and this is often the culprit for breast-fed babies too, but not necessarily.
For a breast-fed baby it can be any food that the mother is eating. A tiny proportion of what the mother consumes goes through into the breast milk, and these few molecules of food are enough to provoke a reaction in the child.
Bottle-fed babies
For bottle-fed babies, proceed as follows:
•    Change to an alternative milk-free formula (see box on p. 66). Wait two weeks before concluding that there is no improvement – recovery can take time – and try another type of formula before you decide this is not the answer.
•    If there is no joy with alternative infant formula, consider the possibility of relactation: stimulating the flow of your own breast milk once again. Breast-feeding support groups (see page 255) can give you advice. Avoid all dairy products while breast-feeding and take a calcium supplement.
For babies who are old enough, and who have severe symptoms, early weaning is one option, but this must be done very carefully:
•    Keep all dairy products out of the baby’s diet – read labels carefully on prepared foods and know all the different names used for milk (see page 173). Test beef cautiously as it shares some proteins with milk.
•    To avoid new food sensitivities developing, keep eggs, fish. wheat, chocolate and oranges off the menu until the child’s first birthday, then introduce them gradually. Avoid peanuts and other nuts for three years if possible.
•    Keep maize (corn) out of the diet for the first six months, because it is a common ingredient in formula feeds, and the child may have become sensitive to it. Note that some medicines contain corn syrup, but this will only affect those who are very sensitive. A pharmacist can check the full list of ingredients in medicines, and suggest alternatives.
•    No food should be given to the baby every day, or in large amounts. You can use unusual starchy foods, such as sweet potatoes, yams, culnoa and millet (see p. 195), to ring the changes. These all make excellent baby foods.
•    Never force a child to eat any food that is disliked. Try serving it again, once or twice, but give up if there are still fierce objections to the smell or taste – these are often a sign of intolerance or allergy.
•    Ask your doctor to refer you to a paediatric nutritionist so that the diet can be checked. A calcium supplement will probably be needed. Other vitamins or minerals may also be lacking.
Breast-fed babies
For breast-fed babies, the approach is quite different – the main focus here is on what you, the mother, eat and drink.
Firstly, start keeping a food diary, and a record of the baby’s symptoms. Are there any detectable patterns? Does the colic get worse if you drank red wine on the previous day, for example? Note that sometimes the time-gap is more than a day, but it should be reasonably consistent for any one food.
At the same time, eliminate all items other than breast milk from the baby’s diet, including:
•    any solids (e.g. baby foods)
•    fruit juice
•    medicines or vitamin drops that contain other ingredients (e.g. colouring or corn syrup)
•    nipple creams containing arachis oil (peanut oil).
Ask your doctor or pharmacist for alternative versions of medicines or vitamins, without added ingredients. Give boiled water to make up for fruit juice. Wait a week or so to see if things improve.
For the next stage, cut out coffee, tea and all alcoholic drinks. Allow a week for this, and continue with the food/symptom diary meanwhile. If there is no improvement, go on to the next stage, while still avoiding coffee, tea and alcohol.
For the next stage, compile a list of suspect foods, based on your food diary. Add to this list:
•    cow’s milk and all milk products
•    any foods that you craved when pregnant
•    any foods that you normally eat in large amounts
•    anything you dislike but have been eating because it’s ‘good for you’ or ‘good for the baby’
•    any of the following foods if you eat them regularly: eggs, wheat, oranges and other citrus fruits (lemons, grapefruit etc.), tree nuts, peanuts, fish, chocolate, chicken and beef.
Once you have your list prepared, talk to your doctor. Say that you would like to try eliminating cow’s milk for two weeks to start with, and then – if the colic has not cleared up – all the other foods on your list as well (again, for two weeks). You will need to take a calcium supplement. If there is strong opposition to your plans, based on a fear that your diet will be inadequate, ask for a referral to a nutritionist. Obviously this needs to be arranged promptly. The fear of under-nutrition, which is dangerous for both yourself and the baby, is a very reasonable one, but with sensible precautions any mother can safely carry out this investigation.
Eat at home during this time, as you cannot possibly know all the ingredients in cafe or restaurant meals. Read the labels on packaged meals and watch out for synonyms (see pp. 172-4).
If your baby recovers, and you want to pinpoint the problem food so that your diet becomes less restricted, you can test foods individually. Wait until there has been no sign of colic for a week. Choose one food and eat a portion every day for a week. If the colic does not reappear, cut out this food again and choose a second food to test – again, eat this daily for a week. Stop eating the food sooner if the colic returns. (Foods that proved safe can be reintroduced again later, but you need a break after the testing week.) Test cow’s milk last.
Some babies get better during the exclusion phase but do not respond to any of the foods when tested. The temporary break from the problem food seems to be all they need to lose their sensitivity. In such cases, the mother can go back to an unrestricted diet, but not to exactly the kind of diet she ate before – no food should be eaten every day, nor in large quantities, or the colic may return.
Many babies get over their sensitivity after one or two months without the problem food, so it is worth testing again after a while, especially if you are eating a very restricted diet.
Where cow’s milk turns out to be the offender, goat’s milk or sheep’s milk might be tolerated, but wait until the baby is completely free of symptoms and experiment cautiously. Alternatively, drink one of the new milk substitutes now available (see p. 183).
If the baby clearly responds to a food in the mother’s diet (for example, cow’s milk or peanuts), this food should be given cautiously when first introduced to the child after weaning, in case he or she has a true allergy to it. An allergy test may be helpful in deciding whether to introduce the food at all.

Elimination diet
An elimination diet is a method of diagnosing idiopathic food intolerance (see p. 74) and certain other

forms of food sensitivity where indirect tests, such as skin tests, are unhelpful. The principle of the

elimination diet is very simple. It begins by removing from the body every food that could possibly

cause a reaction, and seeing if this produces a symptom-free state. If it does, the elimination diet

then presents the body with different foods, each in its pure form, to see which ones cause symptoms.
While the principle is simple, the practicalities of the elimination diet can be much more complex, and

it is vital to understand the details fully before you start. There is absolutely no room for

‘cheating’ with this diet – one mouthful of cake is enough to ruin the whole thing. You need forward

planning and a lot of self-discipline, backed up by a good stock of the permitted foods for moments

when hunger overcomes you. Some cooked foods, stored in the freezer in individual portions for quick

defrosting, are a great help.
Doing an elimination diet incorrectly is not just a waste of time. Some people acquire new

sensitivities during the diet, which may make it very much more difficult to do a second elimination

diet. So plan ahead and get it right first time.
The planning stage
First of all, start an accurate symptom diary. This will give you a precise picture of how bad things

are now, before you try any dietary measures. A detailed daily symptom record, covering a period of

about two weeks, can be very useful, whether or not you actually do an elimination diet. It can serve
as a baseline against which to judge the effects of any future treatment.
Before you begin an elimination diet, you must see your doctor and ask if it is safe for you to do the

diet. Read through the next four pages first – the more you know about elimination diets, before

talking to your doctor, the better.
There are some conditions where, although an elimination diet can be very helpful, it should not be

attempted without full medical supervision. Two main causes for concern exist:
•    For people who are undernourished to start with, the elimination diet may be too demanding – it

is difficult to eat enough calories during the first few weeks of the diet, unless an elemental diet is

used as a supplement (see box on p. 196). If you are underweight, or have rheumatoid arthritis or

Crohn’s disease, the possible use of elemental diets is something you should discuss with your doctor.
•    With certain diseases (see list that follows), the testing stage may induce severe symptoms.

Sometimes these can be life-threatening and need immediate medical attention.
Medical supervision during food testing is recommended for anyone with these conditions:
•    Crohn’s disease – testing can bring on a prolonged relapse. Very small amounts of food should

be tested initially, and the quantity slowly increased.
•    Brittle asthma – after a period of avoidance, a culprit food can bring on a severe and possibly

life-threatening asthma attack.
•    Atopic eczema – the risk of reactions is higher if skin tests are positive (see p. 198).
•    Chronic urticaria – occasionally there is an immediate reaction to an offending food. It is

advisable to test foods in very small portions oust a mouthful) at first. If there is no reaction

whatever after four hours, a normal portion can be tested.
Note that an elimination diet is not suitable for anyone with true food allergy (see p. 62). If you

have ever had an immediate reaction to any food, or any symptoms in the lips or mouth, testing foods

can be dangerous. Caution is also necessary if you have ever reacted to a food with violent vomiting

and/or diarrhoea some hours after eating. This could be due to an infection, of course, but such

symptoms can also, very rarely, result from true food allergy (see p. 64). Finally, if you have ever

suffered anaphylaxis from any cause – not just food –the testing phase of an elimination diet might be

risky. Ask your doctor’s advice.
Once you have your doctor’s permission to try the diet, work out how the stages of the diet will fit in

with your life over the weeks or months ahead. Until it is over, eating food made by other people is

virtually out of the question. When eating away from home, you must either take prepared food with you,

or just eat very simple foods – such as permitted fruits or nuts. Think about the practicalities of

carrying food for meals away from home.
Finally, devise the diet you will follow during the exclusion phase (see right), locate shops that sell

the more unusual foods, and stock up on everything required.
You will continue to eat a lot of these foods for the first few weeks of the testing stage, so you may

want to buy extra stocks and refrigerate them for
longer storage, especially if the sources of supply are some distance from your home.
Note that food ingredients in medication could interfere with the results of the elimination diet. For

example, if you are very sensitive to maize (corn), the cornflour that is added to many antihistamines

and other drugs could create much confusion. Food-free medicines are available – talk to your

pharmacist about this initially, then to your doctor if you need a different prescription.
The exclusion phase
During the first part of an elimination diet, you exclude all the foods that you normally eat, plus any

closely related foods. For example, if you normally eat oranges, you should avoid all other citrus

fruits, including lemon, limes and grapefruit, even though you do not normally eat these. If you

normally eat plenty of broccoli, you should omit all its relatives, such as cabbage, kale, spring

greens and cress.
The best way to conduct the exclusion phase is not to follow a set menu, such as the well-known

‘Iamb-and-pears’ diet, but to draw up your own list of permitted foods. This can include foods that you

have never eaten before, and those you eat rarely.
The list should run to at least ten items. One problem with an exclusion phase that consists of only

two foods (as in the ‘Iamb-and-pears’ diet) is that you are bound to eat a huge amount of these foods.

This is asking for trouble if you have a tendency to food intolerance, because you can quite quickly

become sensitive to new foods if eating them in large amounts.
Your list of permitted foods should include:
Some starchy items. These are essential for keeping hunger at bay: try some of the more exotic root

crops, such as sweet potatoes, yams, dasheen and cassava. These are available in large supermarkets and

in small shops catering to Indian, African, Chinese and Caribbean communities. (Cook them as you would

potatoes. In the case of cassava, it must be boiled, not baked.) You can also eat parsnips, turnips,

chestnuts and pumpkin. Tapioca, sago, buckwheat, millet, quinoa and sorghum are other possibilities: a

health-food shop is a good source of some of these. Use rice if it is not normally part of your diet.

Do not include sweetcorn or maize meal, even though you do not normally eat these –corn products are

very widely used in packaged food, and sensitivity to corn is not uncommon.
Several fruits and vegetables that you don’t normally eat. Exotic produce such as mangoes and okra can

help a lot in keeping the diet tasty. Avocados, which are very rich and nutritious, can be included if

you don’t eat them often.
Some protein items. For carnivores, this is the easy part – any meat that you don’t normally eat is

suitable. Consider turkey, rabbit, pigeon or game, for example. (Soak rabbit meat in salt water

overnight to get rid of the strong taste, if you dislike this.) Strict vegetarians have more problems

here, since goat’s milk, sheep’s milk and all birds’ eggs are disallowed – their proteins are much too

similar to those of normal milk and eggs. Soya products such as tofu should definitely be avoided, as

should other pulses initially, because sensitivity to these is a possibility among vegetarians. Quorn,

or mycoprotein, could affect anyone sensitised to yeast, and should not be included. Fortunately the

exclusion phase is fairly brief, so a low intake of protein will not be disastrous. Including some nuts

on your list of permitted foods will help, as these contain protein. If nuts are part of your normal

diet, you may have to resort to rarely eaten kinds such as macadamias, cashews or pistachios.
Elemental diets
An elemental diet is a powder that contains all the nutrients the human body needs but is free from the

substances in food that provoke allergic and intolerance reactions. It is mixed with water to create a

complete substitute for food. Originally designed for space travel, this totally synthetic form of

sustenance is also known as ‘the astronaut’s diet’.
Used alone during the exclusion phase, elemental diets are the basis for the ultimate – and

theoretically foolproof – elimination diet. They sustain you through the exclusion phase, and continue

to provide your basic diet during the testing phase.
For anyone with multiple food sensitivity, using an elemental diet circumvents the problem of finding

ten or more safe foods with which the elimination diet can begin.
Those who are underweight can also benefit from using an elemental diet, simply as a calorie-boosting

supplement during the exclusion phase and testing phase.
Unfortunately, elemental diets taste fairly unpleasant and are quite expensive. You
may need a prescription, so talk to your doctor. Ideally you should get an elemental diet that does not

contain sucrose (sugar).
Some items that make good snacks. Nuts, pumpkin seeds, sunflower seeds, fresh fruit and dried fruit are

all useful for times when you are away from home, or feel hungry between meals. At the outset of the

diet, use only unsulphured dried fruit –available from health-food shops. At a later stage, you can

test ordinary dried fruit (all of which is treated with sulphur preservatives – see box on p. 207).
A cooking oil, preferably one that you have not used much in the past. Use this fairly liberally, to

keep the calorie content of your diet at a reasonable level
Note that this is a very plain diet – you eat the permitted foods and absolutely nothing else. You

cannot use spices, herbs or other flavourings. Salt is allowed, but sugar is out, as are tea, coffee,

alcohol and all soft drinks. You must drink only mineral water and pure juices from permitted fruits.
Don’t use canned or packaged versions of the permitted foods. Buy raw food and cook it yourself. The

idea is to avoid food additives and other contaminants, such as those from the linings of cans.
Throughout this phase, and the next, you must be very careful not to eat too much of any one food.

Never eat any food every day, and stay away from any food that you begin to develop a real passion for

– this is always a bad sign in people with food intolerance. It is better to go a little hungry

(assuming you are not underweight to start with) rather than binge on any of the permitted foods.

Acquiring new sensitivities is all too easy.
Assuming you do have food intolerance, and you have excluded all the foods that affect you, there

should be a complete clearance of symptoms within 7-10 days. The response is usually unmistakable. A

partial or slight response is probably just a coincidence, and should be discounted, except for those

with rheumatoid arthritis (see below).
Be warned that you may feel a great deal worse before you get better. For those who do have idiopathic

food intolerance, the first 5-6 days of the diet can be very unpleasant – usually they suffer the same

symptoms as before the diet, but far more severe.
Some conditions, such as Crohn’s disease and rheumatoid arthritis, may require a longer exclusion

phase, but there is no point in continuing beyond three weeks. Bear in mind that long-term structural

damage to arthritic joints may prevent a complete recovery. A partial but sustained improvement in the

joints, accompanied by a distinct improvement in general health, suggests that food could well be

playing a part in causing the disease, and that it is worth going on to the testing phase.
Symptoms that are only intermittent, such as chronic urticaria or migraine, pose a special problem. You

need to decide, before starting the diet, how long the exclusion phase should continue in order to give

you a clear sign that your state of health is improved. A symptom diary is vital here. If, for example,

your symptom diary shows that you sometimes have a week that is symptom-free but you never get through

two weeks without an attack, then your exclusion phase should continue for two weeks.
You should only go on to the testing phase if you improve during the exclusion phase. If you do not

improve, you have excluded the possibility of food intolerance, and can give up the diet.
The testing phase
This part of the diet, which is sometimes called the reintroduction phase, takes about eight weeks. It

requires careful observation of your symptoms, and constant self-discipline about everything you eat.

You should not stop or delay the testing unless you are ill – it is vitally important to complete it as

quickly as possible.
Foods have to be reintroduced one at a time, with a space between in which symptoms can be observed. It

sounds simple, but this is where errors can easily occur.
During this phase, as well as noting your symptoms daily, you should also record absolutely everything

you eat.
For the first 2-3 weeks you should test foods that are unlikely to cause symptoms. Start by testing

fruits, vegetables and meats that you do not eat very often normally, but which you do like. If they

pass the test, you can use them to vary your diet. This will make life much easier and reduce the risk

of developing new sensitivities.
Next test foods that you do eat reasonably often, but not every day. Leave the most likely culprits –

the foods you eat very regularly, such as wheat and milk products – until you have established a safe

diet that contains at least 25 different foods. This safe and relatively varied diet should be the

backdrop against which you test staple foods.
The testing procedure changes over time, because your sensitivity may decline as the diet progresses.

During the first eight weeks, you should test one food each day, eating a normal-sized portion for

lunch or supper. A reaction to the food might occur quite soon after the meal, or some hours later. Any

symptoms that occur within the following 24 hours should be provisionally attributed to that food.
Unfortunately, bowel symptoms can sometimes take longer to develop – up to 48 hours. This can confuse

things when a new food is being tested every day.
There may also be uncertainty about intermittent conditions such as chronic urticaria. You may not be

absolutely sure that the problem really responded to the exclusion phase. If so, when the symptoms

recur during the testing phase, this may be due to a food, or it may just be coincidence.
Should there be any doubt about which food caused a particular set of symptoms, cut out all the suspect

foods for now, and retest them after a couple of weeks, using a three-day testing procedure (see

below).
When a reaction does occur to a food, stop all testing and go back to the safe diet until you feel

completely better. But don’t wait too long before resuming testing. You need to get through most of the

testing within eight weeks because, for some people, intolerance to the foods begins to fade after

that.
This does not mean that the intolerance has been ‘cured’, unfortunately. A period of eating the food

regularly will soon bring the problem back.
If you are still testing foods after eight weeks, you must change to three-day testing – eat a normal

portion of the food every day for three days, stopping only if you get symptoms. Should you have no

reaction to the food by the end of the fourth day, you can consider it safe. (But leave it out of your

diet for at least another four days.)
There are some special procedures for testing certain foods:
•    When you test wheat, even if it is quite early on, use the three-day test procedure (see

above). Reactions to wheat can be very slow. (If you have rheumatoid arthritis, you should spend a full

five days testing wheat, and eat it at least twice a day.) Don’t use bread to test wheat because this

also contains yeast and other ingredients. Use a pure wheat cereal such as Shredded Wheat – moisten it

with fruit juice if you cannot have milk. Note that some people who react to whole-wheat are sensitive

to the wheat germ, and can tolerate refined wheat, as in white bread and flour. For others only white

flour is a problem – they are usually reacting to additives in the white flour. Careful testing will

sort out these issues.
•    Test milk before cheese and butter. You may react to one but not the others. If you react to

fresh milk, wait a few weeks, then test evaporated milk. Later, you can test goat’s milk and then

sheep’s milk. Some people can tolerate these, but must be very careful not to consume too much of them.
•    You can test yeast using Marmite or yeast-based B-vitamin tablets. Do this before you test

mushrooms, •    At some point, test a canned food. This is to check for reactions to the lining

material used on cans. Choose something that contains no other ingredients or additives, such as

carrots. Test it first in a frozen or fresh form, so that you are sure you don’t have a reaction to the

food itself.
•    Throughout the testing period, continue with cooking all your own food from scratch. At a

fairly late stage in the testing, when you have tested most foods, spend three days eating packaged

food. The idea is to eat a wide range of different food additives all at once. Read the labels

carefully (see p. 172) to check that all the food ingredients are ones which you have already tested

and found safe. You are unlikely to react to these packaged foods, but if you do, you should then

conduct tests with all the individual food additives. You may need some help from a dietitian for this

(see p. 201).
Testing becomes more and more uncertain after 12 weeks. If you
have not completed it by then, reintroduce all the untested foods.
Should your symptoms come back, cut out all those foods again,
then test them individually.
What next?
For anyone who recovers during an elimination diet, and successfully identifies their problem foods, a

period of complete abstinence from those foods follows. After about a year, it is worth testing the

foods again, as the sensitivity may have subsided. (Don’t do this if you have rheumatoid arthritis –

see p. 23.)
If, after a year or two, you find that a food no longer makes you ill, don’t go back to your old ways –

remember that you must only eat the food occasionally. Once every three or four bays is a good rule of

thumb for a food to which you were previously intolerant. You might get away with having it slightly

more often than this, but never go back to eating it daily. If it starts to become your ‘favourite

food’ again – the thing you fancy more often than anything else – watch out.
Good nutrition is an important issue for anyone avoiding certain key foods. If you have cut out all

milk products, for example, you should probably be taking a calcium supplement, unless you eat a lot of

other calcium-rich foods. Ask your doctor to refer you to a dietician or nutritionist if you feel you

need help.
An elimination diet for children with eczema
Before putting your child on any kind of restrictive diet, it is vital that you talk to your doctor.

The risks of malnutrition are far higher for children, and there can be serious long-term consequences,

such as stunted growth or impaired intelligence. You must therefore have medical consent and

supervision for an elimination diet.
For young children with atopic eczema, there is rarely any need for a stringent elimination diet, such

as that described on pp. 194-7. Children are usually sensitised to only one or two commonly eaten

foods.
In the case of recently weaned infants, it is enough to simply cut out individual foods, one at a time.

Avoid each food for two weeks, while observing symptoms carefully.
For older children a simple elimination diet, with an exclusion phase which avoids just the most likely

culprits, works well. The foods that you should exclude at the outset are:
•    any food which has given a positive skin-prick test (see p. 69)
•    any food which you think may have caused digestive symptoms, such as diarrhoea, either now or

in the past
•    eggs, milk and all milk products
•    beef and chicken
•    citrus fruits (oranges, lemons etc.)
•    food additives.
If the child’s skin is no better after a week of this diet, cut out the following foods as well:
•    peanuts and other nuts
•    soya
•    fish
•    wheat and maize (corn)
•    tomatoes
•    lamb.
If there is no response after another week, food is unlikely to be contributing to the eczema.
For the testing phase, use three-day testing, as described on p. 197, if you have fewer than ten foods

to test. Use one-day testing if you have more than ten foods to test.
You should begin by testing a very small amount of the food. Wait ten minutes for any symptoms (not

just skin symptoms – the mouth or stomach may also be affected) then give a little more if nothing has

happened. Build up gradually to testing a normal portion of the food.
A more cautious approach is required for children who give positive skin-prick tests to foods, or have

a history of symptoms in the mouth or digestive tract. They are more likely to suffer severe symptoms

in the lips, mouth and throat – the type of reaction associated with food allergy. Emergency medical

treatment may be needed. You can see if there is any likelihood of a severe immediate reaction to foods

by starting with a test on the face, and then the outer lip (see box on p. 23). If nothing happens, it

is probably safe to go on to the next stage – giving the child a very small amount of the food to eat.

However, you should have medical supervision for Rare reactions
Very occasionally, atopic eczema sufferers on milk-avoidance diets develop a sensitivity reaction to

calcium supplements. There is no scientific explanation for this, but it has been very well documented

in two children. Should you encounter this problem, the answer may be some alternative natural source

of calcium: sardines or other small fish, eaten whole, are one possibility, assuming your child will

eat fish. A dietician can advise on how much is needed per day.
There has also been one well-documented report of a child reacting to mineral water. When the water she

usually drank was changed to another brand, her eczema cleared up. This is very unlikely to be a common

problem.
this procedure in the case of foods that gave positive skin tests. If your child has both severe eczema

and additional symptoms (such as nettle rash, or symptoms in the mouth or digestive tract) it may be

advisable to have medical supervision when testing all foods.
Bear in mind that atopic eczema naturally fluctuates a great deal. To observe the effects of trying out

a food, you need the child’s skin to be in a steady state. That means being absolutely consistent about

applying steroids and moisturisers, avoiding (for the period of testing) any stressful situations that

could provoke a flare-up, not exposing the skin to sudden doses of irritants or airborne allergens, and

keeping scratching under control. Be aware of other factors that could muddy the waters by provoking a

flare-up of eczema – such as teething, or a cold (see p. 44).
If certain foods are identified as provoking eczema symptoms, and you decide to cut the food from your

child’s diet, a nutritional supplement may well be needed. Ask your doctor to refer you to a

nutritionist or dietician.
Other diagnostic diets
These diets are not used by (or even known to) the majority of doctors. While some, such as the

low-nickel diet, have been subjected to rigorous scientific testing and have shown their worth, others

have not been tested scientifically. The evidence in favour of them is purely anecdotal – in other

words, doctors have used these treatments repeatedly and observed good results with some of their

patients. That is not hard science, but it is how innovations in medicine often begin.
There are few risks with any of these diets – the number of foods to be avoided is small, and you are

most unlikely to become malnourished. Your doctor should not object to you trying any of these diets,

however sceptical he or she may be about its possible benefits.
Low-nickel diet
This diet is sometimes of benefit to adults with eczema. There are various pointers which indicate that

the diet may help, as described on pp. 55-6.
Make sure that you have absolutely no contact with any nickel (e.g. in jewellery, jeans studs, watches

or hair clips) throughout this diet, and for at least two weeks before starting it.
Ideally you should also stop treatment with steroids or antihistamines a week or so before starting the

diet. This allows any improvement to be easily observed. Obviously you should get your doctor’s

permission to do this.
The diet could take anything from six weeks to six months to take full effect. Some people have a

complete clearance of their eczema, while for others there is a partial but distinct improvement.
The foods with a high nickel content, which should be avoided as far as possible, are:
•    shellfish
•    green beans and peas
•    beansprouts and lucerne sprouts
•    dry beans and lentils (pulses) of all kinds; soya protein and products containing it (e.g.

vegetarian sausages and burgers)
•    spinach and kale
•    lettuce, leeks
•    wheat bran (avoid bran cereals and other products; replace wholemeal bread with white bread, or

eat it in moderation only – you can get plenty of fibre from fruits and vegetables; do not eat

multi-grain breads at all)
•    oatmeal, millet and buckwheat
•    raspberries, prunes, pineapple, figs
•    chocolate and cocoa
•    tea from drinks dispensers (restrict intake of other tea and coffee, and don’t make them too

strong)
•    peanuts, hazelnuts, almonds and marzipan
•    liquorice
•    sunflower seeds, linseed
•    baking powder, in large amounts
•    vitamin or mineral preparations that contain nickel (check the label carefully), Nickel is also

found in drinking water, and absorbed from certain cooking utensils, so:
•    Do not use items plated with nickel (e.g. tea balls, some tea strainers, egg beaters). The

extremely shiny appearance of nickel makes these easy to recognise.
•    Do not cook acid fruits in stainless steel pans, since the acid leaches some nickel out of the

stainless steel. An enamel cooking pot is safe.
•    Minimise the amount of tinned food that you eat.
•    In the morning, run off the first litre of water from the tap, as this may contain nickel

released from the tap itself.
Several other foods and drinks seem to aggravate the skin of nickel-sensitive people, even though the

foods are not rich in nickel. These foods and drinks should also be avoided:
•    beer, wine
•    herring, mackerel, tuna
•tomatoes, carrots, onions, apples; oranges and other citrus fruits, including their juices.
Low-chromium and low-cobalt diets
Skin sensitivity to chromium or cobalt can, very occasionally, result in a tendency to react to these

same metals when consumed in food or drink (see pp. 56).
Unfortunately, both chromium and cobalt are essential for good nutrition, so avoiding them is fraught

with problems. You would need the help of a really good dietician, or a doctor with a particular

interest in nutritional problems, to guide you through a diet of this kind.
The only measure you can safely take at home is to cut down on excessive consumption of these metals,

for three weeks only, to see if this produces any improvement in your symptoms. If it does, that should

encourage you to seek expert help for a more thorough avoidance diet.
In the case of cobalt sensitivity avoid:
•    all canned and bottled beer.
In the case of chromium sensitivity avoid:
•    beer, wine and cider
•    yeast extract and yeast tablets
•    black pepper
•    calf’s liver
•    wheatgerm and wholemeal bread
•    cheese.
If you also have nickel sensitivity, avoid nickel-rich foods (see p. 199) at the same time.
Low-histamine diet
Histamine in food is mostly produced by bacterial action. The majority of people can break down any

histamine they eat, as long as the amount is not excessive (see box on p. 67).
Temporary susceptibility to histamine may accompany viral hepatitis or other liver conditions.
A permanently impaired ability to detoxify histamine is relatively unusual. When it does occur it can

result in symptoms such as chronic urticaria, migraine or recurrent headaches. A low-histamine diet may

help in these cases. All of the following should be avoided:
Very high histamine content:
•    red wine, champagne
•    tuna, sardines
•    Emmenthal and Camembert cheeses.
High histamine content:
•    beer, white wine
•    anchovies
•    Gouda, Roquefort, Stilton and all other well-matured cheeses
•    salami and other well-matured sausages, Westphalian ham
•    sauerkraut
•    spinach
•    tomato ketchup.
If you improve only partially on this diet, this may indicate that you are on the right track

(histamine is indeed the problem) but that the bacteria in your gut are undermining your efforts with

the additional histamine which they generate. You can investigate this possibility by trying a

low-carbohydrate diet, as described on p. 53.
Low-amine diet
Naturally occurring substances called amines, found in many different foods, can have a drug-like

effect on the blood vessels, making them open up a little and so increasing the blood flow. The effect

is usually small, but some people are more susceptible than others. A low-amine diet is worth trying if

you have chronic urticaria or migraines, and have not improved with other treatments. A low-amine diet

can also be useful in atopic eczema: amines in food are not a basic cause of eczema, but they can

aggravate the rash by increasing blood flow to the skin. To begin with, cut out all foods listed below:
Very high amine content:
•    all cheeses except cottage cheese
•    dark or plain chocolate
•    yeast extract (Marmite etc.), miso, tempeh, tomato paste, tandoori spice mix, stock cubes,

ready-made sauces •    cola drinks, orange juice, tomato juice
•    any dried, pickled or smoked fish
•    sausages, pies and smoked meats, beef liver, chicken skin
•    broad beans, spinach
•    sauerkraut
•    almonds.
High or moderate amine content:
•    milk chocolate
•    soy sauce
•    beer, wine and cider
•    pork, including bacon and ham, salami, chicken liver, offal
•    all fresh or tinned fish, except white fish
•    all nuts except chestnuts and cashews
•    sesame seeds, sunflower seeds
•    avocados, aubergines, mushrooms, tomatoes, broccoli, cauliflower
•    olives and olive oil
•    oranges, lemons and other citrus fruits
•    pineapples, bananas, raspberries, strawberries, pineapples, plums, grapes, dates, figs, kiwi

fruit, passion fruit.
Continue for at least three weeks, and longer if your symptoms are normally intermittent. if you

improve, you can then experiment with reintroducing small portions of foods from the second list, three

or four times a week. Gradually build up to a higher intake, but cut back if your symptoms return.
Organic diet
The objective here is to avoid pesticides, i.e. chemical sprays applied to kill fungi and insect pests.

This may be helpful for people with chemical intolerance (see p. 84).
`Chemical-free’ or ‘unsprayed’ food (crops grown without pesticides) will do just as well as 100%

organic food (which is grown without either pesticides or artificial fertilisers).
The highest intake of pesticides is from fresh fruit and vegetables, so if your budget is tight,

concentrate on buying organic or chemical-free versions of these. If you have a garden, growing some of

your own food will reduce the cost.
You can also reduce the pesticide content of ordinary fruits and vegetables by:
•    Storing them for as long as possible before using them, because the pesticides break down quite

quickly
•    Always peeling them. With difficult-to-peel items such as peaches and tomatoes, pour boiling

water over them and leave them to stand for a few minutes first, as this loosens the skin. Rinse in

cold water, then peel.
•    If peeling is not possible, washing them very well with soap or detergent, then rinsing them

thoroughly
•    Cooking them, as this drives off some of the pesticides; avoid inhaling the steam and ventilate

the kitchen well while doing this.
You should drink mineral water from a reputable source, or use a very high-quality water filter (not a

jug filter).
Additive-free diet
Food additives are occasionally the culprit in chronic urticaria (see p. 53). At the same time as

avoiding additives, people with chronic urticaria should cut out other potential culprits – alcohol,

spices and all aspirin-like drugs (see box on p. 151).
An additive-free diet may also be of value for some people with chemical intolerance (see p. 84).
In the case of children with Attention Deficit Disorder (ADD), also called Hyperkinetic Syndrome, the

role of additive-free diets is a contentious issue (see p. 81).
An additive-free diet is very healthy but quite hard work. It means making all your own food from 100%

fresh, unmodified produce (you cannot have bacon or ham, and even things like cooked chicken and

ready-to-eat salad can contain some additives; so does most restaurant food). Note that wines, beers

and other alcoholic drinks can contain many additives without declaring them on the label. (German

bottled beer is an exception here.) Baked goods sold unwrapped can also contain many additives without

declaring them.
Stop using toothpaste unless it is an additive-free brand. You can buy such toothpaste from a

health-food shop – or use sodium bicarbonate powder instead. Drink mineral water or filtered water (you

need a good-quality filter for this, not a jug filter).
Medicinal drugs can contain colourings and other additives, so you should try to get additive-free

versions. Talk to your pharmacist about this initially.
Assuming the symptoms clear up, testing can begin, but you will probably need medical help to work out

exactly which additives are at fault. It is difficult to organise these tests at home, because most

foods contain such a mixture of additives.
With chronic urticaria, there is the possibility of quite severe reactions on testing, so medical

supervision is desirable. You can undertake cautious testing with small amounts of tap water, spices

and alcohol at home, but make sure you are in a position to get emergency medical help if you need it.

Aspirin or aspirin-like drugs should not be tested at home. Life-threatening reactions are common in

sensitive individuals, and temporary avoidance can heighten your reaction.

Allergens in Food
Anyone with true food allergy or coeliac disease needs to be very careful about avoiding certain foods. The information given here is aimed mainly at such people, rather than those with food intolerance (see p. 74), who can usually tolerate small amounts of their offending foods. However, some of the basic information given here is relevant to those with food intolerance as well.
There are different levels of sensitivity even among those with true food allergy. The ‘exquisitely sensitive’ can react to unbelievably minute traces of the food, and for them life is especially difficult. The same is true of some coelicacs, who can be affected by the tiniest quantity of gluten.
These people are a small minority. The level of vigilance required of such people will not be necessary for most people reading this book, so don’t get things out of proportion. While it is vital to be sensible about avoiding your problem food, it is also important not to become over-anxious.
Buying basic ingredients
Cooking for yourself is the safest way to eat for those with true food allergy and coeliac disease. There are relatively few hazards, but do beware of well-meaning assistants in health-food shops who try to sell you some exotic package of grain or flour – spelt or kamut or triticale, for example – reassuring
you that it is ‘definitely not wheat’. Be well informed about the different forms of your problem food and the names under which it is sold (see pp. 172-5).
Oils made from foods such as corn or peanut sometimes cause concern. Ordinary refined oils have been so thoroughly processed that they actually contain no allergenic proteins, so you can safely use these. Bottles of gourmet walnut oil and almond oil are a different story however, and should be avoided if you have nut allergies. Sesame oil is not purified either and can provoke serious reactions. With any oil, if you are unsure how safe it might be, go by the smell. Oils that smell or taste like the food from which they are made could well contain allergens.
Those with allergy to tuna can usually eat tinned tuna because the processing makes it safe. The allergens in fresh fruit and vegetables are generally inactivated by cooking too, so jams and tinned fruits tend to be safe – but test very cautiously. Cooking does not have much effect on other food allergens, apart from eggs. In rare cases, cooking can create allergens (see box on p. 186).
If you share your kitchen with others, and are highly sensitive, check that all cooking utensils are truly clean before use. Coeliac should watch out for breadcrumbs in the butter dish, jam or toaster. Where small children are allergic to a food, it may be best to keep the culprit out of the house entirely.
Genetic engineering and food allergy
Many people with food allergies are very concerned about the possibility that genetic engineering could introduce allergens from one plant species into another. This concern seems to be shared by government officials and those in the food industry, who are being extremely vigilant and cautious at present. As long as this attitude continues, there should be little danger to food allergy sufferers.
Finding food in funny places
If you are suffering some inexplicable reactions to non-food items, it might, just possibly, be a food reaction. Some latex gloves contain the milk protein casein, for example, added as a manufacturing aid.
Buying packaged foods
There are several different issues here:
• the need to read labels carefully for allergenic ingredients described by unfamiliar names (see p. 172)
• errors in the packaging used (see pp. 174-5)
• contamination by minute traces of a food substance due to processing machinery not being cleaned adequately. Cartons of fruit drink have occasionally been contaminated with traces of milk because the same production lines were used for packaging milk drinks. Tofu desserts made in ice-cream factories can also become contaminated with milk. These tiny traces of a food will only affect the most highly sensitive individuals, but contamination by nuts can involve large pieces and affect anyone with nut allergy (see p. 174).
• foodstuffs which are used as part of the production process
and leave a tiny residue in the finished item (see p. 174).
Be very cautious indeed about ready-made food that is unlabelled, such as that from bakeries and home-made stalls. Egg is frequently used as a glaze on baked products, nuts may lurk within, and milk or wheat can turn up in the most unlikely places.
Restaurants, cafes and takeaways
The majority of fatal and near-fatal incidents involving people with true food allergy are due to restaurants, cafeterias and canteens. Takeaways can also be a problem except in the case of the large chains such as McDonald’s, where ingredients are standardised. It is alarming that highly allergenic foods (e.g. peanut) are sometimes used – yet far from obvious – in recipes and sandwich fillings where they would simply not be expected. Anyone with peanut or shellfish allergy should be ultra-cautious about Chinese, Thai or Malaysian cooking – but those with milk allergy should find a haven here, because milk is not part of these culinary traditions.
The simplest solution is to eat very plainly when you go out –steak and salad, for example. Steer clear of casseroles and thick soups, where you can’t see what’s in it (the occasional chef throws in peanut butter to thicken the mix…). Food wrapped in pastry is best avoided for the same reason. Desserts and cakes are risky for anyone with nut, egg or milk allergy.
You must insist on accurate information about the food before you taste it. If the counter staff, the waiter or the waitress
is unsure of the ingredients, ask them to check with the chef, or with the label on pre-packaged food. Be persistent and never eat anything unless you are sure. Make eye contact with the person concerned, and learn to be a good judge of character. Your life could depend on telling the difference between the waiter who knows the facts about the food and the waiter who is being blandly reassuring for the sake of a quiet life.
It is a great mistake to pick out the pieces of offending food – kiwi fruit from a fruit salad for example – and eat the rest. There is often enough allergen left behind to cause anaphylaxis in the highly allergic individual.
Those who are extremely sensitive to the offending food must also consider the problem of contamination in the kitchen. Grills and fryers in restaurants and canteens can become contaminated with fish allergens or nut allergens (e.g. from nut cutlets) and these can be transferred to fried potatoes or other foods, provoking anaphylaxis in the highly allergic individual. One person with fish allergy died in this way. Sesame seeds can also contaminate equipment, work-surfaces or bakery counters.
Parties and buffets
Milk, egg, shellfish or nut allergies can make it especially hazardous to eat buffet or party food. Regard everything with suspicion. Cocktail snacks with nuts or peanut paste hidden inside are a particular problem.
When fish allergy isn’t fish allergy
Anisakis is a parasitic worm that infests fish and can sometimes survive the
cooking process to infect humans. The worms are easily thrown off by the human immune system, but the body is primed to make IgE antibodies should
it ever encounter Anisakis again. Another meal of parasitised fish – even if the Anisakis worms are all dead this time, and only the allergens remain
will provoke a massive IgE-mediated reaction, leading to anaphylactic shock. This problem is usually misdiagnosed as allergy to fish itself.
Other inconsistent reactions to food can be due to contaminants such as antibiotics, preservatives, other food additives or (especially in the case of shellfish) naturally occuring toxins.

Suffering from a long-term illness, especially if it is severe and sometimes limits activity, can easily make a child feel different from other children, and ‘not good enough’. Children with allergies, especially those with severe asthma or food allergies, may also be very frightened and anxious. At the same time, such children often feel that they have to protect their parents by not revealing their fears.
Children may also think that their illness is a punishment for something they have done wrong. Their guilty feelings can be so powerful that they may not confide in you unless you spend time talking with them about their illness, and encourage them to share their feelings with you.
One of the most valuable things you can do for children with allergies is to build up their self-esteem. This is especially important when they first start school, because they have to adjust to other children there, and learn how to deal with questions about their illness, as well as some unkindness.
For children whose allergies limit what they can do physically, or restrict some normal activities, try to find other interests and hobbies that the child can do well. When talking with the child, always emphasise the positive things – the difficulties that you have overcome together in the past, the measures that the child can take to keep the symptoms under control (such as stopping scratching, applying creams, or using a preventer inhaler) and the areas of Iife where he or she is particularly successful. As the child gets older, introduce the idea that coping with illness makes you a stronger, kinder and more resolute person, one who can cope with any of life’s challenges. Show the child how much you value their maturity and perseverance.
Pay attention to what the child’s friends are
saying – a bit of eavesdropping is allowed – and be prepared to counteract any negative messages. Teach your child to be strong and self-confident about choosing their friends, and to prefer those who are sensible, understanding and supportive. Ask casually about what schoolteachers and other adults say when you are not around, because they can, without meaning any harm, undermine a child’s confidence with thoughtless remarks.
For children with problems that are potentially life-threatening, such as true food allergy, your natural anxieties as a parent can lead you to be overprotective. This can make the child feel smothered, but letting go is far from easy. You somehow have to find a middle path that works for you both.
With asthmatic children, focus on letting them live as normal a life as possible. Avoid saying ‘no’ automatically to things that might induce an asthma attack – such as running around outdoors in cold weather. Take some small risks, and let the child make the decision sometimes – he or she will gain a lot from taking the responsibility, especially if the decision is the wrong one.
This is the only way for children to learn how to manage their own condition. The sooner you can begin letting go, the better the child will cope in his or her teenage years, when it really will be necessary to make some difficult decisions without your help.
A pitfall for parents
In bringing up a child with allergies, remember that there should never be any ’secondary gain’ from illness – absolutely no advantages to having the eczema get worse (easily done by scratching) or starting an asthma attack (some children can bring one on by breathing in a particular way).
If your child has to take time off from school because of ill-health, ask the teacher for work that can be done at home, and check that it really is done. Children who are allowed to benefit from being ill can establish an unhealthy pattern for dealing with life’s difficulties (see pp. 94-5), which may be long-lasting. Such a mind-set can seriously limit a child’s development.
Incidentally, the ’secondary gain’ from illness may be quite altruistic in nature. It can include stopping parents from arguing, or from nagging a naughty brother or sister, as well as more obvious things such as getting a parent’s attention – so be aware of all the circumstances in the family that are affecting the child.
Sometimes a child realises, unconsciously, that attending to illness gives a parent welcome distractions from emotional problems and a comforting feeling of being needed and useful. The allergies can become part of the structure of a family, the glue holding everyone together.
Conversely, long-term illness can tear families apart: according to recent research carried out in the United States, divorce is more common in families where a child suffers from severe asthma.
Doctors frequently notice that severe eczema also can create a lot of tension in the home.
If you feel that a child’s illness is affecting the family badly – in whatever way – talk to your doctor, or someone else who you trust. You may need the help of a counsellor or family therapist to sort things out.
Children and medicines
Parents often feel very anxious about all the medication an allergic child uses. On the whole, the drugs prescribed for allergy are very safe, and only children with severe disease are at risk of significant side effects. These children will be carefully monitored by the doctor.
Needless to say, if you can cut down on the drugs by reducing allergen exposure, avoiding irritants (e.g. tobacco smoke) and implementing some of the other measures described in this book, you should do so. But if the child still needs drugs to control the symptoms, it is far better to accept them than to let the child struggle with all the discomfort, limitations and distress that the illness imposes.
Parents who are very concerned about drugs should talk openly to the doctor about their fears. If there are differences of opinion about drugs within the family, try not to expose the child to the disagreements. Sort out a joint policy in advance and always present a united front to the child. Be consistent and reassuring about drug use, otherwise the child may feel confused and anxious about the situation – or may even learn to manipulate it.
The asthmatic child
Children with asthma should have a management plan (see p. 96) and may benefit from using a peak-flow meter (see p. 97). Once your child is old enough to comprehend the difference between preventers and relievers, explain that using the preventer regularly keeps asthma under control, which means no sudden attacks and less need to use the reliever in public — something which most children find intensely embarrassing. You should oversee the child’s treatment closely until the age of seven or eight, then gradually let the child take over some of the responsibilities.
Coping with food allergy
The following concerns true food allergy (see p. 62), which can be life-threatening, not idiopathic food intolerance (see p. 74).
Protecting a child with severe food allergies is a major task. You will find it enormously helpful to be in contact with other parents who are facing the same challenge. The practical details are everything here, and you can benefit from other people’s ingenuity in solving day-to-day problems. Several support groups exist (see p. 255), offering a wealth of advice.
For very small children, the main task is to ensure that everyone who looks after the child understands exactly what can and can’t be eaten. Child-minders and baby-sitters should spend time with you as ‘apprentices’ seeing what is involved in preparing food for the child – this is far better than just giving verbal instructions. Also make sure that everyone knows how to use the adrenaline auto-injector (see pp. 98-9).
Once children start going to parties, you should always stay at the party for the whole time, and supervise your child closely. Take food that your child can safely eat, but which other children can also share. Some parents put a label on toddlers warning other adults that certain foods are taboo – for children under reading age this is probably acceptable, and does allow you to relax a little, but with older children the dangers of being teased or stigmatised should always be borne in mind.
Plan ahead all the time. Keep a snack box in the car containing food that the child can safely eat. Whenever you go on a trip, however short, have some safe foods with you, in case you get stuck somewhere and the child gets hungry. If you go out to eat, exert maximum caution about the restaurant food (see p. 111). Some parents take along a guaranteed-safe, but super-delicious sandwich or burger, and ask the restaurant to warm it up in a microwave (where appropriate) and serve it at the same time as the other food. If you do this, be sure the staff understand that the food must not touch any other food.
At home, some parents opt for everyone eating the same allergen-free food, on the basis that this makes for being ‘a real family’. Others, finding this too problematic or expensive, make a virtue out of the allergic child having a different meal. ‘I try to make her feel special about having her own food. The allergen-free dinner or cake always looks and tastes really good.’
As children get older, and more independent, you need to educate them thoroughly about avoiding the offending food. Equip them for difficult situations by role-playing. Act out being offered a tempting item of food by another child, and being jeered at for refusing. Act out suffering an allergic reaction to food and getting help quickly, even though people around don’t understand and are uncooperative.
Allergies and schools
When your child starts at a new school, creche, or kindergarten, request a meeting with staff and teachers to talk about the child’s allergies if there is any likelihood of these becoming a problem. Do this well before your child starts at the school, so that any necessary changes can be made. If your child has a serious food allergy or severe asthma, you may have to make several visits because there are usually a number of different people you should meet, and follow-up sessions may be needed with some staff. If all this sounds daunting and ‘not my style’ then you need, for the sake of your child, to develop your skills in dealing with people and being assertive. Talk to a counsellor, or look for suitable training courses.
In addition to ensuring that the school takes good care of your child’s health (see below), you should also discuss wider issues of adjustment to school life. Teasing or bullying can be a problem for children with any kind of health problem. Ask the teacher to keep an eye on your child and ensure that he or she is coping well – for example, that there is no difficulty about using an inhaler in front of other children when necessary.
Eczema
Ensure all staff realise that the skin rash is not infectious, and that they are aware of the need to communicate this to other children. The appearance of the skin can create a lot of problems with class-mates, and teachers need to be alert for taunting remarks or hurtful nicknames.
Unfortunately, children with eczema are very susceptible to infections caught from others, such as impetigo (see p. 44), but you can’t really protect children from such infections without isolating them socially. The best way to tackle this problem is to deploy all the available treatments so that your child’s skin becomes stronger and more resistant.
Food allergy
If your child has food allergy, go and see the catering manager personally. It may be helpful to take some printed material on food allergy with you, plus lists of synonyms for food ingredients (see pp. 172-4) where appropriate. Concentrate on building up a good relationship with catering staff, while ensuring that they understand how dangerous certain foods can be to your child.
Many parents feel more relaxed if they supply their child with a packed lunch that they know is allergen-free. This is often a good strategy, but don’t be complacent. Most allergic reactions in schools involve food given or traded by another child with entirely good intentions. Some schools with food-allergic children have set up a ‘no trading food’ policy, which seems to work well. Other schools establish milk-free or nut-free tables in the canteen, so that friends can sit together and trade food safely. (The mothers of the other children sitting at these tables need to be well versed in food avoidance, of course, so that their packed lunches are as safe as your own.) In the United States, schools have sometimes tried banning nuts or peanuts altogether, where there is a nut-allergic student, but this does not work well.
Some parents prepare a printed information sheet about their child’s food allergy, with a photograph of the child, and put these up at strategic points around the kitchen and canteen area. This information can include instructions on how to deal with anaphylactic shock (see below) and who to contact in an emergency.
Finally, include the art teacher in your rounds – foodstuffs are often used in art and craft projects.
Anaphylaxis
For children with severe food or insect-sting allergies which can lead to anaphylaxis, check that everyone at the school understands the potentially fatal nature of this condition. Key staff must know how to recognise anaphylactic shock and exactly what to do: show them how the adrenaline injector kit works. You could take along an old one, so that they can practise (see p. 150). Injector kits and adrenaline inhalers must be within easy reach, never locked in a cupboard.
Repeat this educational process at the beginning of each new school year, and before school trips. As an additional precaution, your child should wear a bracelet or pendant (see box on p. 95) that informs medical personnel about his or her allergies –this is also vital for children with latex or drugs allergies.
Asthma
If your child has asthma, ask what arrangements are made for inhalers. Children who can take responsibility for their own treatment should keep their inhalers with them. For younger children, the inhaler should be in the classroom, somewhere that is easily accessible (never locked away) and should be taken along during breaks and mealtimes. The child must always be able to get to the inhaler quickly: even a small delay in using it when an attack occurs can have dire consequences. Make sure everyone at the school understands this, that they know how to recognise an attack, and how to react. Assure the teacher that there is little danger of an asthmatic child overdosing, and if other children take a few puffs they will come to no harm.
If the teacher seems to believe that asthma is a psychological problem (some still do), go and see the head. Suggest that a local asthma nurse or doctor comes in and talks to the staff and pupils about asthma.
Ensure that the teacher knows about the effects of cold air and exercise on asthmatics. Talk to the games teacher or sports coach, and the playground attendants. It is vital that the games teacher is encouraging but understanding towards asthmatic children. They should never be told to continue exercising if they feel breathless.
Allergens and irritants in school
Schools today often have soft furnishings and carpets – these may be full of dust mites. If your child is allergic to mites, and if allergy symptoms are frequent at school, have a look around the classroom and see if this might be the cause. Before discussing the problem with the school, learn all you can about dust mites (see p. 114-117) so that you can assess whether proposed solutions to the problem would actually work.
Pets are common in classrooms and they can cause allergic reactions in sensitised children. Moulds flourish in many school buildings, and will affect a child with mould allergy. Poor ventilation is sometimes a major problem in school buildings, especially those where windows cannot be opened.
Irritants in school air include glue, paint, the solvents from felt-tip pens, disinfectants, air fresheners and the fumes produced during science lessons. Make sure the science teacher is aware of the risks and always uses a fume cupboard if irritant gases such as nitrogen dioxide or sulphur dioxide are likely to be given off during an experiment.
Applying sunscreens to children’s skin is now routine in many schools and preschools. Teachers probably won’t think to ask permission, so if your child is sensitive to any common ingredients of creams or sunscreens, let them know in advance.

Food Intolerance
The comments of those who have recovered from food intolerance after many years of ill-health are always memorable. ‘It’s like getting my life back again,’ said one woman. ‘I had actually forgotten what it felt like to be well,’ said another, ‘the effect of cutting out certain foods was just amazing.’
For most of those with food intolerance, the disease begins very subtly and gradually – first one symptom (persistent and unexplained diarrhoea, perhaps) then, some years later, another (migraine or headaches) and then, when a few more years have passed, another symptom (such as joint pain or muscle aches). Steadily increasing levels of irritability, `fuzzy-headedness’ or inexplicable tiredness may accompany this decline in health.
Most patients have no idea that all these symptoms are connected until they try an elimination diet, and everything clears up at once, quite dramatically. As one former sufferer described it: `Some of the stuff that got better – well, I’d been like that so long I thought it was just the way I was –grumpy and exhausted, and feeling terrible if I didn’t eat meals on time. It was an absolute revelation to feel completely OK again.’
What does ‘food intolerance’ mean?
In this book, food intolerance means any reaction to food where the immune system has no proven central role.
All the people I have described so far have idiopathic food intolerance, which means, food intolerance with no established mechanism – in other words, doctors can’t say exactly how it is caused. This is a highly controversial area.
The definition of food intolerance used in this book means that it also includes metabolic abnormalities, which do have a well-established cause. These are due to defective enzymes (see upper box on p. 75).
The question of what words mean is a key part of the debate over idiopathic food intolerance. At one extreme, you may come across doctors who call this problem ‘food allergy’, using the original meaning of the word ‘allergy’ (see p. 6). (Some of these doctors use terms such as delayed food allergy and masked food allergy, to point up the distinction from true food allergy, but not all do.) Using the word ‘allergy’ in this context causes a lot of aggravation and confusion, so the term ‘food intolerance’ has, for a long time, been widely accepted as a useful one that avoids unnecessary conflict.
You will also hear the term ‘food intolerance’ used to mean idiopathic food intolerance only – this is probably the most common usage. When the term is used in this way, metabolic abnormalities are being thought of as a separate entity altogether.
A new twist has recently been added to this long-standing wrangle over meanings. When mentioning food intolerance in their literature, some of the major medical organisations (those who dispute the very existence of idiopathic food intolerance) now say simply ‘food intolerance e.g. lactase deficiency’. To anyone familiar with this field, it looks suspiciously like an attempt to redefine ‘food intolerance’ so that it means nothing more than ‘metabolic abnormalities’. The idea seems to be that, if you deny a disease a name, it will go away!
In the medical wilderness
The main text of this article is about idiopathic food intolerance, a disease with a distinctly dubious reputation among doctors. Because it is so controversial, few doctors actually look at the evidence that it exists – which is in fact quite strong (see box on p. 77). Such evidence is simply ignored in most of what is written by the major medical organisations debunking idiopathic food intolerance.
This lack of medical recognition is very unfortunate for patients with idiopathic food intolerance, whose debilitating symptoms could be eliminated, rather than simply being treated (usually to little effect) with drugs.
This prejudiced attitude to idiopathic food intolerance also plays into the hands of those offering bogus diagnostic tests and phoney treatments, often at a very high price. These practitioners
– who have moved in to fill the gap left by conventional medicine
– are a considerable part of the problem, helping to give idiopathic food intolerance a bad name.
The waters are muddied even more by the fact that some people who believe themselves to have food intolerance are actually suffering from psychological problems, which they prefer to attribute to food. Many more have picked up on food intolerance as something rather glamorous to suffer from, inspired by all the media reports about food intolerance among celebrities. All these patients are a good source of revenue for the less scrupulous fringe practitioners and are unlikely, therefore, to be discouraged from their beliefs.
Fortunately there are enough conventional but open-minded doctors, often GPs, who have come to realise, through experience with their own patients, that elimination diets have a remarkable curative effect for some people. The ones who benefit are often the doctor’s ‘old faithfuls’ – those with long-term multiple symptoms, who have been referred to innumerable specialists and treated with all kinds of drugs, but who never get much better. The conventional view of such patients is that they have psychological problems that are being expressed as physical symptoms. This may well be true for some – but others have idiopathic food intolerance.
One of our enzymes is missing
Metabolic abnormalities are a distinct type of food intolerance. Unlike other kinds of food intolerance, metabolic abnormalities have a clearly understood cause: an enzyme that carries out a crucial task in the body’s metabolism is either missing or inept. The problem is generally caused by a defective gene and is therefore inherited.
The most common metabolic abnormality is lactase deficiency leading to lactose intolerance (see p. 79) — this may or may not be inherited. Other metabolic abnormalities include:
trehalase deficiency, lack of the enzyme which breaks down a substance in mushrooms and most other fungi, including yeast. galactosaemia, a defect in the enzyme which processes galactose, one of the sugars found in milk (cow’s or human). This is a serious disease and sufferers must avoid milk scrupulously.
fructose intolerance, which is extremely rare. Those affected have an unpleasant taste in the mouth on eating fruit and other sources of fructose, so avoidance is no particular problem.
phenylketonuria, also very rare. Those affected are usually identified early in life, by a routine blood test.
Is it just placebo effect?
Doctors who doubt the very existence of idiopathic food intolerance will say that people who recover on an elimination diet are just experiencing placebo effect — a psychological response that operates with any treatment, whether effective or ineffective, simply because people believe that the treatment will work. But this is to ignore certain facts:
• Placebo effect produces a fairly small improvement in most people — you have to be very suggestible to feel enormously better. By contrast, when people respond to an elimination diet (the standard method for diagnosing idiopathic food intolerance —see p. 194) they usually have a sudden and dramatic improvement.
• Most of those with idiopathic food intolerance have had it for years and tried all sorts of treatments. They have often experienced some small benefit from these, probably placebo effect. When they try an elimination diet, they have a response that is in a completely different league.
• The idea that all the different symptoms are linked has never occurred to many people who try an elimination diet — they are often trying it for just one symptom, and are staggered when everything clears up. Placebo effect relies on expectation.
• Placebo effect doesn’t last very long — it fades over the ensuing weeks and months. Avoiding the culprit food usually produces a lasting improvement for those with idiopathic food intolerance.
Symptoms
The symptoms of idiopathic food intolerance come on slowly after eating the offending food, and the foods to blame are often those eaten very regularly, such as wheat or milk. Consequently, the symptoms from one meal tend to overlap with those from the previous meal and people with idiopathic food intolerance are more-or-less unwell for most of the time. It Is usually not obvious that food is at fault.
All the symptoms of idiopathic food intolerance are common ones that can be caused in other ways. And no two patients have exactly the same set of symptoms.
(As far as doctors are concerned, neither of these attributes gives the disease a respectable air.)
These are some of the symptoms commonly reported:
• headache or migraine
•diarrhoea, sometimes with bloating and wind; this is often diagnosed as irritable bowel syndrome (IBS)
• in children, stomach aches
• occasionally constipation
• nausea and indigestion
• joint pain
• aching muscles
• a constantly runny or blocked nose (this could be perennial allergic rhinitis linked to food – see p. 68)
• glue ear (see p. 29)
• fatigue and a general feeling of vague ill-health.
Asthma and eczema, triggered by specific foods (see p. 68), can also be part of the picture.
In babies, colic is often caused by food intolerance, including foods the mother is eating which come through into the breast milk in tiny amounts (see p. 202).
Less common symptoms include:
• recurrent mouth ulcers
• stomach or duodenal ulcers
• chronic urticaria (see pp. 50-53)
• swelling (angioedema).
The following diseases have also been linked to idiopathic food intolerance in some patients:
• Crohn’s disease
• palindromic rheumatism (intermittent episodes of joint inflammation)
• rheumatoid arthritis.
Psychological problems such as depression, anxiety, or hyperactivity in children can sometimes be due to food (see p. 80) but it is rare for such psychological effects to occur without any physical symptoms.
Remember that every single one of these symptoms and conditions can be caused in some other way. However, the constellation of migraine/headache, joint pain and diarrhoea is highly characteristic of idiopathic food intolerance.
How might intolerance be caused?
No one knows how idiopathic food intolerance is caused. There are probably many factors involved, with a slightly different mix of factors in each patient. This would help to explain why the symptoms are so extraordinarily varied, with no two sufferers exactly alike.
Although symptoms accumulate over the years, some people can in fact pinpoint the moment when their problems began. ‘I had this terrible bout of diarrhoea from eating too much melon. I lived near a farm and they were free, because of a glut, so I just gorged myself on them. Although I was over the diarrhoea in a couple of days, I was never what you’d call “regular” after that, and the least thing would upset me. Eventually the doctor said it was irritable bowel syndrome. When the other problems began, ages afterwards – headaches and hypoglycaemia and fatigue – it seemed like something quite separate. I never associated them in my mind with the diarrhoea.’
Bad diarrhoea can clear the intestines of their beneficial bacteria, known collectively as the gut flora (see p. 204), and this is probably what initiates food intolerance in such cases. Large doses of antibiotics (as are sometimes given before an operation, e.g. a hysterectomy), or prolonged and repeated courses of antibiotics, given for glue ear or acne, can also disrupt the gut flora and lead to food intolerance. A study of hysterectomy patients has shown that antibiotic treatment before the operation tends to result in irritable bowel syndrome – a common symptom of idiopathic food intolerance – afterwards.
A few interesting observations suggest that minor metabolic abnormalities – a defect in certain detoxification enzymes – may sometimes play a part in idiopathic food intolerance. This is especially likely where there is intolerance to food additives, or where there are behavioural symptoms (such as hyperactivity) or symptoms involving the nervous system (such as migraine).
A third factor that could play a part for some patients are food-derived exorphins. These are fragments of proteins (called peptides) produced by the digestion of food proteins. They happen, probably by pure coincidence, to resemble the substances called endorphins that we all produce for ourselves. Endorphins
are our internal painkillers. They modify nerve impulses in the body and brain, reducing sensations of pain, and improving the sense of well-being. The receptors to which they bind are the same receptors that bind morphine and heroin - it is the intensive stimulation of these receptors that makes these drugs so effective.
Food-derived exorphins may sound like the stuff of science fiction, but they have actually been demonstrated in the digestion products of wheat and milk. They may exist for other foods as well. They are nowhere near as strong as morphine, but do seem to improve mood.
These exorphins may explain the strange observation (made repeatedly, by a great number of initially sceptical doctors) that patients with idiopathic food intolerance often eat huge amounts of their offending food, and ‘can’t live without it’. Often they eat the food several times day, sometimes at every meal. With a ubiquitous ingredient like wheat or milk, this is not particularly difficult - wheat cereal and milk for breakfast, a cheese sandwich at lunchtime, pasta with a creamy sauce for supper, a milky drink and biscuits at bedtime.
Any of these abnormalities is likely to be just one factor in a multi-factorial disease.
Diagnosis
Unfortunately there are no simple accurate tests for idiopathic food intolerance. The kind of tests you may see offered commercially (in advertisements in health magazines for example) are very inaccurate, and a waste of money. Consequently, the only way to diagnose idiopathic food intolerance is through an elimination diet, in which you cut out all the foods you commonly eat, and then -if you get better - test them one by one.
It sounds easy but it isn’t, so make sure you read all the instructions for doing the diet before you start (see pp. 194-7). You should also see your doctor and get his or her approval. Some symptoms - such as severe diarrhoea or headaches -should be investigated by conventional methods first, in case there is some serious underlying cause.
The first step in diagnosis is to decide if a food really is the cause of the symptoms, and the second step is to identify the food or foods concerned.
The first step is crucial. One of the problems with the diagnostic tests that are advertised - such as those using samples of hair or blood - is that they begin with the second step. In other words they assume that food is the problem (see p. 93).
When it comes to the second step, remember that although common foods are often the culprits, almost anything that is eaten can cause idiopathic food intolerance. Every patient with this problem is different in the foods they react to.
Treatment
Avoidance of the food is usually the best treatment for idiopathic food intolerance - however most people do not have to avoid their problem foods for ever. After a while - it could be six months or it could be three years - you can usually go back to eating it again, but in moderation. You must never start eating the food in large amounts again, and it is best not to eat it every day - certainly not at almost every meal, which is the usual pattern for cow’s milk and wheat in the Western diet.
If you find the restrictive diet too difficult, you could try desensitisation treatment (see pp. 210-13). This can work very well.
The patients who should avoid the culprit food indefinitely are those with Crohn’s disease and rheumatoid arthritis: a severe and irreversible relapse can occur otherwise.
The evidence
The evidence for idiopathic food intolerance is more substantial than its opponents would have you believe.
One very well-conducted and interesting study involved children with severe migraine who were investigated by a research team at Great Ormond Street Hospital in London. These are children who are very difficult to treat successfully by normal means. On an elimination diet, 88% of those children got better — an astonishing number. Not just their migraine, but all sorts of other symptoms as well, including aching limbs, runny noses, asthma, eczema, diarrhoea, wind, mouth ulcers and hyperactivity. Some of these children also had epileptic fits, and even this symptom cleared up on the diet, recurring when culprit foods were tested.
A notable feature of this study is that, of the five researchers involved, four were deeply sceptical at the outset. Their report notes that they ‘embarked on this study believing that any favourable response, such as that claimed to substantiate the dietary hypothesis, could be explained as a placebo response. The positive double-blind controlled trial… provides clear evidence that a placebo response was not the explanation.’
Other studies with good scientific credentials have demonstrated a role for idiopathic food intolerance in adults with migraine, and for sufferers from irritable bowel syndrome and Crohn’s disease. There are also good studies of individual patients with rheumatoid arthritis and palindromic rheumatism (an episodic form of inflammatory arthritis) who have responded dramatically to avoidance of a particular food. Some of these patients were given several double-blind challenges and showed changes in certain immunological tests, as well as joint symptoms, when challenged with the offending food. This suggests that the immune system could be playing some part in these food reactions.