Posts Tagged ‘Minimising’

Few newborns are already capable of mounting an allergic reaction to dust mite. Actual symptoms of allergy may not appear for several months or years, but the essential first

step – making the allergy antibody, IgE, against the mite allergens – seems to have occurred already for some babies.
In situations where IgE does the job it is supposed to do –protecting against worms and other parasites (see p. 13) – this advance programming of the immune system before birth

has definite advantages. A child whose mother is infected with parasites is born with the ability to make IgE against those parasites, even though he or she has had no direct

contact with them before birth. The baby’s immune system has been forewarned of the likely hazards of life in the outside world.
While this is obviously valuable in conditions where parasitic infections are rife, emerging into a carpeted and well-upholstered world with IgE against dust mite already in the

bloodstream is a serious disadvantage, because it can pave the way for rhinitis and asthma. Given the trouble caused by dust-mite allergen, some doctors think that women should

try to reduce their exposure to it during the second half of pregnancy, so that little or none reaches the unborn child. At present it is not known for sure if this can make a

difference to the risk of allergies developing in a child, but it seems plausible.
What is pretty clear, from several previous studies, is that the level of house-dust mite in the home immediately after birth can make a distinct difference as regards the

chance of allergy developing. Minimising a newborn baby’s exposure to dust mite is worthwhile, and the measures needed to achieve this are described on pp. 244-5.
Carrying out these measures will raise the level of dust-mite allergen in the air temporarily, so it makes sense to do the work in the early stages of pregnancy (or – even

better – before conception), rather than expose yourself and the foetus to a tremendous burst of allergen later on in pregnancy. Or, get someone else to do the work, and stay

away while it is done.
There may be other potential allergens which you should try to eliminate from your home before the baby arrives, such as mould allergens (see p. 122).
Pregnancy
First and foremost – don’t smoke while you are pregnant, or afterwards (see box on p. 107). Any other smokers in the household should smoke outdoors.
What about your diet during pregnancy? Certainly you should eat a good balanced diet with plenty of fruit and vegetables. Taking a small supplement of vitamin E, or eating

plenty of sunflower seeds and oil, would be a good idea. Women with a low
intake of vitamin E and antioxidants (see p. 206) during pregnancy run a higher risk of having an allergic child.
Should you also avoid any foods? Food allergens, such as those from cow’s milk, do reach the foetus, passed from the mother’s blood to the baby’s blood via the placenta. And a

few babies are born already capable of making IgE against food allergens. On the basis of these findings, some doctors have suggested that avoiding potentially allergenic foods

(such as eggs, cow’s milk and peanuts) during pregnancy might help to reduce the risk of food allergy. However, evidence from research trials in which pregnant women followed a

restricted diet, and their children were later studied for allergies, does not show any convincing benefit. And in some studies, the women on restricted diets have not gained as

much weight as they should, and the babies have been slightly below average weight at birth. Most doctors now think that dietary restrictions during pregnancy are not worthwhile

– it is more important to eat well and get enough nutrients.
It does seem sensible not to overeat any particular food during pregnancy, although there is no scientific evidence on this point (simply because researchers have not yet looked

for such evidence). In particular, don’t overdo it with milk and milk products. Make sure you get enough calcium, obviously, but don’t force yourself to drink huge amounts of

milk, especially if you have any distaste for it. Talk to your doctor, midwife or health visitor about the possibility of a calcium supplement, if you dislike milk.
Breast-feeding
‘The cornerstone of allergy prevention is breast-feeding,’ according to Dr Erika Isolauri of Tampere University Hospital in Finland.
At one time, this would have been a controversial statement, but there is now a substantial body of scientific evidence to support the ‘breast-is-best’ idea in relation to

allergy prevention. A number of different studies have shown that exclusive breast-feeding, up to at least four months of age, reduces the risk of developing food allergy or

atopic eczema (or both) in the early years of life.
Exclusive means exactly that – no solids at all until after four months (and six months is better), and no supplementary feeds with infant formula, which is made from cow’s

milk, and therefore contains cow’s milk allergens. Unfortunately, it is sometimes far from easy to ensure that formula feeds are not given just after birth, by well-intentioned

nurses on the maternity ward. Given what we now know about the immune system of the newborn, this is the worst possible time to be delivering an onslaught of potentially

allergenic cow’s milk proteins.
Quite apart from the immediate effect of introducing cow’s milk allergens to the baby, a bottle can disrupt the development of a good breast-feeding relationship between mother

and child, and may lead to the early abandonment of breast-feeding.
Why should this happen? Firstly a different technique is needed for sucking on a bottle teat, and your baby may never develop the knack with nipples if given bottles at an early

stage. Secondly, allaying the baby’s hunger with a bottle can also mean that he or she demands less at the next breast-feed – and since the mother’s milk supply is partly

influenced by the level of demand, this can be detrimental. Some experts believe that occasional bottle-feeds can start a downward spiral of ever-diminishing supply from the

mother.
Dr Arne Host of the Department of Paediatrics at Odense University Hospital in Denmark, who has made a special study of breast-feeding, recommends giving a little boiled water

as a supplement during the first 3-4 days of life, if the breast milk supply is inadequate. After that time, the mother’s own supply should increase to meet the needs of her

baby. Introducing bottle-feeds at an early stage can prevent this delicate balance of supply-anddemand from ever being achieved.
Sometimes (though this is rare) despite everything being done just right, a mother’s supply of milk never quite matches her infant’s appetite. When this happens, and the child

concerned is from an allergy-prone family, the breast milk should be supplemented with an ultra-safe formula feed called a hydrolysate (see box on p. 66).
Hydrolysates should also be used for infants at high risk of allergy who, for whatever reason, cannot be breast-fed. Note that there are two categories of hydrolysate –

extensively hydrolysed formula and partially hydrolysed formula. For the purposes of allergy prevention, an extensively hydrolysed formula should always be used because it has

the lowest risk of causing food allergies.
Preparing to breast-feed
Because breast-feeding is natural, many first-time mothers just assume it will come naturally. Sadly, it often doesn’t.
Cracked nipples are a major obstacle. They are the equivalent of chapped hands, and are often caused by the baby not having ‘latched on’ correctly to the nipple. Help from an

expert breast-feeding adviser, right from the start. can avoid this problem.
Because cracked nipples are so sore, breast-feeding can then become a major ordeal rather than a pleasurable experience as it should be. What is more, infectious bacteria can

enter the breast through the cracks in the skin, causing mastitis, which is painful and may require antibiotic treatment: this is not necessarily a good thing for the baby (see

p. 247).
You can minimise the chance of cracked nipples by making the skin on the nipples tougher and more resilient, so that it does
not crack. Start during pregnancy, in about your fourth month. When you have a bath or shower, rub your nipples vigorously with your flannel for a few minutes. After three weeks

of this, graduate to a soft toothbrush, and brush them gently, then more firmly when they feel ready. Progress to a medium, and then a hard toothbrush.
Breast-feeding support groups can be immensely helpful, when you start breast-feeding, or when you feel things are not going right. Some groups have local advisers. all mothers

themselves with first-hand experience of breast-feeding. Having such an adviser with you, watching you breast-feed your new baby and making suggestions, or pointing out where

you are going wrong, can make all the difference. Look for such a group locally, and establish contact with them well before your due date. You may be able to have an adviser

with you at the birth, to help the baby take his or her first feed: this is of enormous value.
Having prepared yourself, you then have to prepare the nursing staff in the hospital where you will give birth, for the fact that you want to breast-feed exclusively. That means

no supplementary feeds from the staff – not even one bottle. The risks of this practice, in sensitising vulnerable babies to cow’s milk, are still not widely known, so you may

need to be persistent and make your feelings very clear. Talk to your midwife about this well before your expected delivery date, and find out what policy the hospital has about

supplementary feeds. Then see the relevant staff at the hospital.
The nurses are most likely to give the baby a bottle because he or she is crying while you are asleep, and they don’t want to wake you. Staff change all the time, so you will

probably need to put a notice on the crib or cot, to be certain that the baby is never bottle-fed while you are sleeping. If this seems ‘over-the-top’, consider the experience

of British researchers investigating allergy prevention who wanted to ensure that a group of newborns were never given supplementary feeds. They put warning stickers on both the

babies’ cots and the mothers’ beds, as well as asking the midwives and mothers to be very vigilant. Despite this effort, several of the babies being studied were given bottles.
Sometimes nurses give a bottle because they believe that the baby is not getting enough milk from the breast. The idea that mothers “don’t have enough milk”, and that this is

quite a common problem, is part of the medical folklore of breastfeeding today. In fact, true milk insufficiency is very rare. Most cases of poor milk supply arise because a

good breastfeeding relationship between mother and child is never established – and supplementary bottle feeds are partly to blame.
It is entirely possible that your milk supply will not be quite adequate in the first few days, but it should increase rapidly. The best thing, if breast- milk supply is

inadequate, is to give boiled water as a supplement during the first 3-4 days of life (see left).
Some preliminary evidence suggests that mastitis may alter the profile of immune cells in the milk, and that this might possibly increase the risk of the child’s own immune

system becoming allergy-prone. A key preventive measure is not to let the breasts become engorged with milk: the build-up of milk can lead on to mastitis. Learning to express

milk (by hand or with a breast pump) will be useful for times when your breasts feel over-full. Talk to a breast-feeding adviser.
Diet during breast-feeding
Pretty much everything you eat works its way into breast milk, though in very tiny amounts.
The food molecules that get through into breast milk can certainly affect babies who are already sensitised to a food. Cow’s milk is the classic example — cow’s milk proteins

get into human milk if the mother consumes any milk, cheese, yoghurt or other milk products. Babies who have already been sensitised to cow’s milk (by a supplementary

bottle-feed, for example, or even in the womb — see p. 241) react badly to the breast milk, unless the mother avoids all dairy products.
What is less certain is whether the traces of allergen in breast milk — cow’s milk allergen or that from any other food — might be capable of starting off allergy or

sensitivity. Are these minute traces enough to sensitise babies with a strong tendency to allergy? If they are, then mothers of high-risk infants might be well advised to avoid

certain allergenic foods while breast-feeding. Some studies do suggest that there is a reduction in food allergy if breast-feeding mothers avoid cow’s milk, eggs, nuts, fish and

soya. But if this restrictive diet makes your life impossible, then it is better to breast-feed your baby and eat what you like, than not to breast-feed at all.
Unfortunately, some babies do get eczema, in spite of being exclusively breast-fed. If this happens with your child, there are a number of steps you can take to deal with the

problem (see box on p. 248).
Treating the gut flora
Taking a probiotic or bacterial replacer (see p. 205) during the later stages of pregnancy, and continuing with this while breast-feeding, may reduce the risk of atopic eczema

in your child.
Weaning — when and how
The key to reducing the allergy risk for babies is to turn that old political jibe ‘too little, too late’ on its head. Research shows that, with weaning, it is ‘too much, too

early’ that increases the chance of allergic reactions developing. Suddenly presenting an infant of three months with a wide variety of solid foods, including potent allergens

such as eggs, peanuts and fish, can increase the likelihood of food allergy and/or eczema developing. Weaning late, with a limited number of safe foods, should be your goal.
At least four months of exclusive breast-feeding, and preferably six months, is now the standard recommendation for allergy prevention, and it is well supported by scientific

evidence.
But how long should breast-feeding continue after weaning begins? There is little concrete evidence here, but there is a strong belief in the medical community that

breast-feeding should go on for several more months, up to or beyond one year of age if possible, allowing the weaning process to be very gradual. The idea is to introduce new

foods one at a time, alongside breast milk.
As well as allowing the baby’s immune system lots of time to adjust to each new food, prolonged breast-feeding may help in another way as well. Recent research shows that breast

milk contains a great many substances which influence the baby’s immune system, nudging it in the right direction — away from any tendency to allergies.
Avoid those expensive little jars of ready-made baby food. Most contain potent allergens such as cow’s milk, wheat or soya. Making your own baby foods is not difficult, and is

the best way to ensure that your child gets only low-risk foods.
Reducing the risk of peanut allergy
Peanut oil, which contains traces of peanut allergen, is an ingredient of some skin creams. Recent research from the United States shows that babies treated with such creams

were seven times more likely to develop peanut allergy later. In the past, concern has focused on traces of peanut allergen that the baby swallows — either in the breast milk

(because the mother has eaten peanuts) or from her nipple cream. What this new research suggests is that peanut allergens absorbed through the baby’s skin are much
more likely to cause sensitisation. Don’t use any skin products if they have ‘Arachis oil’ or ‘Arachis hypogaea’ in the ingredients list — and steer clear of any cream without a

detailed ingredients list. In the same research study, soy formula also emerged as a risk factor: feeding a baby on this doubled the chance of peanut allergy developing later.

Good health is one of the most important things we can give our kids,’ says Martha, now in her sixties with two grown-up children.
`When I see how bad my daughter’s asthma is, and how hard her life is sometimes because of it, I do feel bad about the fact that I smoked when I was pregnant. But we just didn’t

know in those days. Even my doctor smoked. No one thought anything of it.
`I stopped when she was little, because it seemed to me that her wheezing got worse whenever I lit up. I’m sure that stopping then was better than nothing. It must have helped.
`In any case, there’s no point feeling guilty about things now - that won’t change anything. But if I’d known what damage it could do, I would have stopped sooner.’ Martha’s

regrets stem from the discoveries made in the past decade about the effects of smoking on allergies. We now know that smoking during pregnancy increases the amount of IgE (the

allergy antibody) in the blood of a newborn baby - an indication that he or she is at an increased risk of developing allergies. After the birth, exposing a child to cigarette

smoke continues to encourage high levels of IgE in the blood, as well as irritating the airways and making asthma more likely to develop.
The research on smoking is just one part of a worldwide research effort, during the past 20-30 years, into the possible causes of the allergy epidemic. That research can help

parents who are themselves atopic (allergy-prone) to reduce the risk of passing their allergy problems on to their children.
Who should be implementing these preventive measures? Firstly, any prospective parents who have allergies themselves, or had them as children. They are at higher risk (compared

to a non-allergic parent) of producing a child who is susceptible to allergies. The risk is especially high if both parents have or have had them at some point in their lives.
Secondly, these preventive measures could be worthwhile for parents who don’t have allergies themselves, but who come from atopic families (families with a tendency to allergy).

If you or your partner have brothers, sisters or parents with allergies, you are more likely than the average person to produce allergic children.
Finally, if you already have one allergic child - even though you and your partner don’t have allergies yourselves, and no one else in the family does - there is a

higher-than-average chance that subsequent children will have allergies. Your allergic child is a sign that the genes for allergy are there.
Given the important role that genes play in allergy (see p. 8), preventive strategies make a lot of sense for parents-to-be with allergies in the family.
Unfortunately, this is a topic which often generates confusion - some people assume that if a trait is genetic, it will inevitably come out in the child, and that nothing can be

done to prevent this happening. Although that is true for some inherited traits, such as metabolic abnormalities (see upper box on p. 75), it is not at all the case for allergy.
Developing allergic disease is not inevitable unless a child has a very big dose of the genes that favour allergy. Only a few children - generally those whose mother and father

are both badly affected by allergies - will come into this category. Even with these very high-risk children, following the measures described here will probably help to reduce

the severity of their allergic problems.
For most children at risk of allergies, even though they have some pro-allergy genes, there has to be an unfavourable environment to actually produce allergic disease.

‘Environment’ here means everything external that affects the child, including diet, air quality, allergens, diseases and medical treatment. Factors occurring before birth, such

as the mother’s lifestyle during pregnancy, are also part of the child’s environment. It is the interplay between genes and environment that will decide whether your child

develops allergies or escapes them.
This interaction is not a simple one, however, and different aspects of the environment operate in different ways. Firstly, there are some environmental factors that work at the

most fundamental level -conspiring with the pro-allergy genes to make the overall tendency to allergy far stronger. These are factors such as cigarette smoking by the mother

during pregnancy, or excessive hygiene during childhood, which influence the fundamental make-up of the child’s immune system. Secondly, there are environmental factors, such as

early exposure to house-dust mite or grass pollen, which can cause trouble by provoking specific allergic reactions. Note that factors like these will not become important

unless the allergic tendency is already there.
Efforts to reduce the risk of allergy operate on both types of factor.
On the one hand, there are measures such as quitting smoking or easing up on hygiene, which tackle the allergic predisposition itself. These measures are, in effect, trying to

make a Western child’s immune system more like the immune system of a child from a poor rural village in the developing world, whose chance of developing allergy is very low

indeed.
On the other hand, there are measures such as reducing dust-mite levels, that try to stop the development of particular allergic reactions.
Obviously, if measures of the first kind could be truly successful, there would be little or no need for measures of the second kind. But this kind of success is very difficult

to achieve in modern Western society. Although we can certainly improve matters a great deal, and lessen the tendency to allergy, the conditions that would completely reverse it

are beyond our reach at present. So both kinds of preventive measure remain necessary.
In reading the pages that follow, it is important to keep things in perspective, and not feel excessively anxious about your child. Do what you can, but don’t feel guilty if you

can’t manage everything that is suggested here. And if you already have a child with allergies, please don’t feel guilty about things that might have contributed to this. Only

hindsight is perfect, and you no doubt did the best you could, given the information you had at the time, and the many other constraints and difficulties that you faced. That is

the best that any of us can do.

Allergy and Your Immune System
`The summer used to be such a miserable time for me because I’m allergic to grass pollen. For most of

my life I have had dreadful hayfever, and my asthma would get worse during the summer as well.

Antihistamines knocked me for six, and although there were nose drops that helped a little, they

certainly did not resolve the problem completely. Exam time was always a nightmare when I was a student

- then, as now, it coincided exactly with the pollen season.’
‘Getting a job in Chicago was a turning point in my health. My colleagues were amazed to see me

snuffling through the summer and just accepting that nothing could be done to improve matters. The

whole approach to treating allergies is different there. Eventually someone marched me off to see her

allergist, who said that I should have “allergy shots” and that my health insurance would cover it. The

process was very time-consuming at first, and it took a while to work, but the change is remarkable.

I’ve never regretted having the treatment. Summer is a time I can actually enjoy now.’
Not everyone responds this well to immunotherapy, but for those allergy sufferers who do benefit, this

is an excellent treatment. It tackles allergies right at their source, by teaching the immune system to

react differently to the allergen.
Also known as Specific Immunotherapy (SIT), Incremental Immunotherapy (11T) or simply as

hyposensitisation, this form of treatment was devised by two English medical researchers, Leonard Noon

and John Freeman, who reported their successes with hayfever patients in 1911. Ironically, their

treatment is now less readily available in Britain than in any other industrialised nation. Only a

small minority of British allergy patients receive immunotherapy. The cause of this strange situation

is a ruling made in 1986 by the Committee on the Safety of Medicines (CSM). This states that

immunotherapy must only be given where there is resuscitation equipment available, and that all

patients must wait for an hour after each injection, in case of
side effects. In addition, immunotherapy cannot be used for severe asthma.
The requirement for resuscitation equipment rules out most GP surgeries, and this effectively puts

immunotherapy beyond the reach of many allergic individuals in Britain, owing to the extreme shortage

of allergists and hospital allergy clinics (see p. 89). (In the past, the lack of allergy specialists

meant that most immunotherapy in Britain was given by GPs.)
The CSM ruling was triggered by a number of deaths due to immunotherapy: there were eleven fatalities

between 1980 and 1986, with five of these in the eighteen months just before the report. But almost all

these deaths were due to very basic errors in the way the injections were given – tragic as the deaths

were, the official response to them was inappropriate. Fatal reactions to immunotherapy can be avoided

with close attention to ordinary safeguards (see p. 166-7).
Allergen immunotherapy is still freely available elsewhere in the world, and is regarded as a key part

of allergy treatment. Britain is now out of step with all other developed countries, and most doctors

feel that British restrictions are far too strict.
There are hopes that this situation may change within the next few years, and that more allergy

sufferers may be able to take advantage of this valuable treatment. This could be achieved, in part, by

investing more National Health Service money in allergy clinics and allergy specialists. In addition,

there should be a relaxation of the regulations, so that properly trained GPs can give immunotherapy to

patients who are not at high risk of a fatal reaction. For people whose lives are affected by

allergies, the reintroduction of this treatment (with appropriate safeguards) would be a huge boon.
The uses of immunotherapy
Immunotherapy is mainly used for airborne allergens such as pollen, house-dust mite and mould spores.

Allergies to animals can also be treated with immunotherapy, but the treatment cannot work miracles –

if a cat-allergic person decides to keep the cat, the high dose of allergen inhaled every day limits

the impact of immunotherapy treatment.
People with straightforward allergic reactions affecting the nose and eyes (allergic rhinitis and

conjunctivitis) respond well to immunotherapy. In patients with hayfever, for example, the success rate

(patients showing some degree of improvement) is about 80-90%. When nasal allergies are complicated by

chronic sinusitis or nasal polyps, the chance of success is a little lower.
Some studies of the long-term effects of immunotherapy suggest that, if it is given to children with

hayfever or perennial rhinitis, those children are less likely to develop asthma.
The benefits of using immunotherapy to treat established asthma are less certain. Asthma is a more

complex disease than hayfever, and allergies are only one factor among many (see p. 36), which may

limit the impact that immunotherapy can make. Experience suggests that immunotherapy can be a great

help for an asthmatic with a strong allergic reaction to a single airborne allergen, such as grass

pollen or house-dust mite, but not for other asthmatics. Asthmatics with aspirin sensitivity or chronic

sinusitis are unlikely to benefit.
The value of immunotherapy to children with asthma is a subject of great debate among doctors in the

United States. Some studies suggest that it is of little real benefit, while others are more positive.

One interesting study, that followed asthmatic children for 15 years or more, found that if they were

given a full five-year course of immunotherapy when young, they tended to have fewer asthma symptoms

and need less medication in their late teens and early twenties.
Chronic urticaria (nettle rash) is occasionally due to airborne allergens, in which case immunotherapy

may help. However, immunotherapy is not recommended for atopic eczema. When people with both eczema and

rhinitis try immunotherapy for their nasal allergies, some find that their eczema gets worse.
Insect-sting allergy is a prime candidate for immunotherapy (see pp. 167-8) but food allergy is a

different matter, and is not treated with immunotherapy at present (see p. 168).
Who can get immunotherapy?
As a result of the CSM ruling (see p. 164) remarkably few allergy sufferers in Britain receive

immunotherapy.
Those with insect-sting allergy, who have suffered anaphylaxis (see p. 58), are the most likely to be

offered this treatment. However, even with this frightening and life-threatening problem, which can be

treated with almost 100% success by immunotherapy (see p. 167-8), such treatment is not automatically

available.
A few people with severe hayfever that does not respond well to drug treatment may also be given

immunotherapy. It is worth asking your doctor about such treatment if you feel you would benefit.
How immunotherapy works
Immunotherapy consists of a series of small injections, just under the skin. The liquid that is

injected contains an extract of the offending allergen, for example house-dust mite. The injections are

given at regular intervals, usually once a week, although other schedules are possible (see p. 167-8).
At the outset, a very dilute version of the allergen extract is used, way below the threshold for an

allergic reaction. People who seem highly sensitive, on the basis of their skin tests, start on an

extract that is even more dilute.
For the next injection, a slightly higher concentration of the allergen extract is used, and the

concentration goes on increasing with each successive injection. The idea is to habituate the immune

system to the offending allergen, by very gradually raising the dose. Eventually, when the dose reaches

a level which generally gives beneficial effects, no further increases are made.
If an allergy sufferer reacts badly to immunotherapy injections (see p. 166) on several successive

occasions, the dose may be levelled off before the ideal maximum dose is reached. However, a good

allergist will persist for some time in trying to increase the dose because stopping at a lower level

often results in the treatment being ineffective.
The first stage of immunotherapy, when the concentration of allergen is being increased week by week,

is referred to as the build-up stage. The second stage, when the dose is being kept at the same level,

is called maintenance therapy, and the dose used is the maintenance dose.
There is sometimes an obvious improvement by the time the build-up stage is complete, but not always.

The benefits of the treatment generally appear within six months of reaching the maintenance dose, but

some people have to wait a year or even two before things improve. As the immunotherapy begins to take

effect, symptoms decline and there is often less need for drugs.
A great deal of research effort has gone into finding out what lies behind these changes – in other

words, what is actually happening to the immune system when immunotherapy is effective. The answer is

that a surprising number of different changes may occur and no two allergy sufferers react to

immunotherapy in quite the same way. Frequently there is a shift in the kinds of antibodies the body

produces against the offending allergen. Levels of IgG antibodies (which help to block the allergic

reaction) go up, while levels of the allergy antibody, IgE, tend to stabilise and eventually go down.

The numbers of mast cells (see box on p. 12) may also decline, and they can become less responsive to

the allergen. The balance of power between Th1 cells and Th2 cells may also shift, with the pro-allergy

Th2 cells (see p. 11) becoming less influential.
What can go wrong
The secret of safe immunotherapy is to go at exactly the right speed for the immune system of the

individual being treated. The doctor should look for feedback from the immune system – signs that show

how well it is coping with the steadily increasing dose of allergen – and use these to pace the

immunotherapy schedule.
Going too fast – getting ahead of the immune system’s ability to cope – is hazardous. A major allergic

reaction, called anaphylaxis (see p. 58), can occur, and this is the cause of deaths during

immunotherapy. However, as long as there is injectable adrenaline (see p. 150) and resuscitation

equipment available, even such an extreme crisis can be dealt with safely.
Serious reactions to immunotherapy usually occur:
•    during the initial build-up phase; maintenance therapy is much safer
•    during the pollen season, for those with pollen allergy
•    when a new vial of allergen extract is first being used, because of variations in concentration

(see p. 168-9).
Those most vulnerable to severe reactions are:
•    people with asthma, especially severe or unstable asthma
•    those who have experienced systemic allergic reactions in the past
•    anyone who appears to be extremely allergic, on the basis of skin tests
•    anyone taking beta-Mockers (see box on p. 150).
With care, these fatalities can be avoided. Patients who are given immunotherapy can ensure their own

safety by being well informed about the procedure (see p. 167).
The timing of immunotherapy
There are various different approaches to the timing of immurotherapy. The basic method (which has a

good safety record in the United States where it is very commonly used) starts with injections once a

week. After the maintenance dose has been reached, maintenance injections are given once every 2-4

weeks. The frequency of these may be increased during the pollen season, for people with pollen

allergies.
It is the regularity of the injection schedule that gradually creates, and then sustains, immune

tolerance, so the treatment is only of value to patients who can reliably keep their appointments.
When immunotherapy is successful, it can eventually be discontinued without any reappearance of the

allergic reaction. It usually takes 4-5 years of regular therapy, from the time of the first injection,

to get to this point. The benefits then persist for many years, perhaps indefinitely in some people,

even without any further injections.
Rush immunotherapy
Trying to speed up the process of immunotherapy greatly increases the risk of a severe reaction

(anaphylaxis). However, there are some situations where fast results are needed, and in such cases rush

immunotherapy, also called accelerated immunotherapy, may be used.
During the build-up stage of rush immunotherapy, injections are given every day, or even several times

a day. All the usual safety procedures (see below) are observed with particular care, to reduce the

chance of a severe reaction.
In semi-rush immunotherapy, the build-up injections are given twice a week, and the risks are lower

than with daily injections, but still higher than with weekly injections.
Minimising the risks
If you are lucky enough to be offered immunotherapy treatment under the National Health Service, you

should not feel concerned about accepting the offer. There is very little risk of a bad reaction

because safety procedures are now so stringent.
To minimise the risk of suffering a severe reaction, the doctor will ask you, at each visit, about any

reactions that occurred after your previous injection. Reactions might include redness, itching or

swelling around the injection site, or (more seriously) symptoms elsewhere on the body, such as nettle

rash (urticaria), itchy skin, sneezing, a runny nose, red or itchy eyes, tightness in the throat or

chest, coughing or wheezing. Always make a note of such symptoms, so that you don’t forget to mention

them at the next visit. This is crucially important, as such reactions can indicate that the immune

system is being hurried along too fast.
The doctor will also ask if you have an infection of any kind, as this can alter your reaction. You

should also tell the doctor about any new medicines being taken, as some, such as betablockers (see box

on p. 150), can make a bad reaction to the injection more likely to occur.
Asthmatics can expect the doctor to ask about current asthma symptoms, and to check their peak flow

both before and after an injection. If there are any symptoms, or if the peak flow is less than 70% of

the best-ever value, the injection won’t be given.
Severe reactions can sometimes begin several hours after the injection, so stay within reach of a phone

for about 24 hours. Among United States allergists (who don’t require their patients to wait after the

injection for more than 20-30 minutes) there are some who believe that everyone undergoing

immunotherapy should carry an adrenaline (epinephrine) auto-injector (see p. 150) on the day an

injection has been given, for use in the event of a severe reaction. Anyone who has suffered

anaphylaxis in response to an insect sting will probably have an adrenaline auto-injector anyway, and

this can certainly be used to treat anaphylaxis following immunotherapy. Note, however, that using the

adrenaline is just the first step in treating anaphylaxis (see p. 98) and you must then go back to your

allergist, or to the nearest hospital emergency department, without any delay.
It is sensible to avoid exercise for two hours after an injection. Be extra-cautious during the pollen

season if you are receiving immunotherapy for pollen allergies.
Immunotherapy for insect-sting allergy
`Our daughter has had two really bad reactions from being stung by a wasp. After the second one, the

doctor at the accident and emergency department told us that she nearly died. We got so anxious about

it that we worried every time we left the house in the summer, and it was even worse if she went out

without us. My wife got so upset about it that she wasn’t sleeping well. It was affecting the whole

family badly.
‘Then we heard about desensitisation treatment, and asked our GP, but he said he couldn’t do it.

According to him, they might be able to do it at the hospital, but it might not work, and it was risky

too. We accepted that at first, but then I started doing some research on the Internet, and discovered

that in America and Germany this treatment is absolutely standard – someone like our daughter would

automatically be given it. We felt very angry when we found this out, and went back to the doctor.

Eventually Ann was referred to the allergy department at a hospital, and now she is getting this

desensitisation treatment. I’m pleased about that, obviously, but I still think it shouldn’t have been

such a fight to get it.’
Immunotherapy provides highly effective protection for those with insect-sting allergy, and should be

given to anyone who has had a severe systemic reaction (see p. 60). Some United States allergists also

recommend it for adults who have had a cutaneous systemic reaction (see p. 60), on the basis that they

may well progress to a severe systemic reaction with the next sting.
Studies of people who have suffered severe systemic reactions, and are then treated with immunotherapy,

show that 97% have no systemic reaction to future insect stings. For the 3% who are not fully

protected, the severity of the reaction is much reduced and far less likely to be life-threatening. In

other words, this is an excellent treatment which can save lives.
Targeting the treatment
Choosing the right venom for immunotherapy can sometimes be difficult. Not everyone with insect-sting

allergy sees the insect that caused the reaction. Skin tests may not give the answer either, because

there are often positive reactions to several different venoms. Some of these may be false positives

(see box on p. 91) and it is impossible for the allergist to say which one(s) are actually relevant.

Most allergists will recommend immunotherapy for all of them, using a mixture of venom extracts.
Where the guilty insect was seen and identified, but other venoms also give positive skin tests, a more

difficult decision has to be made. Many allergists carry out immunotherapy for all the venoms that gave

a positive skin test, on a ‘better safe than sorry’ basis. Since there are cross-reactions between

venoms (see box on p. 113), there is some sense in this. Other allergists just give immunotherapy for

the insect that did the deed.
Will immunotherapy against one insect protect against a related insect? With two closely related

insects such as wasps and hornets, which have many allergens in common, it might do – but there is no

guarantee. The problem is that, as well as the shared allergens, each venom also has its own unique

ingredients. It’s impossible to say, with the kind of tests available at present, if an allergic

reaction was to shared allergens or unique ones. So immunotherapy against wasp venom may give

protection against hornet venom, but it will not necessarily do so – and vice versa.
In the case of bumblebee allergy (seen almost exclusively in those, such as horticulturalists, whose

work involves handling bumblebees) a more definite answer can be given – honeybee immunotherapy does

not work. Immunotherapy with bumblebee venom does work, fortunately. The bumblebee extract has to be

obtained from specialist sources.
Injections are given weekly during the build-up phase, unless protection is needed urgently, as with

work-related sting allergy, in which case rush immunotherapy may be used. Once the maximum dose has

been reached, a maintenance injection is needed every four weeks. After a year, this maintenance dose

can be given every 6-8 weeks.
After 3-5 years of immunotherapy, skin tests with insect venoms are usually tried again. If the results

are negative, the immunotherapy will stop. Research now shows that, even if skin tests are still

positive when immunotherapy ends, there’s an 8090% chance that no systemic reaction will occur to

future stings. Some people are not reassured by this, and prefer to continue with immunotherapy for

their own peace of mind. Indeed, research shows that a near-fatal systemic reaction has a long-lasting

psychological impact, and that many people continue to feel anxious despite completing immunotherapy

and reacting negatively to skin tests.
At one time, challenge stings with live insects were given to check whether immunotherapy had actually

worked. Few doctors do this now, but your allergist may be prepared to do a challenge test if you ask.

Adrenaline and resuscitation equipment would be available if a challenge test were used, so any severe

reaction could be dealt with promptly and effectively. The fact that the psychological consequences of

insect-sting allergy are so persistent suggests that challenge tests with live insects may have a

particular value, in demonstrating that immunotherapy has worked. Challenge tests are also helpful for

those who work with stinging insects, such as honeybees and bumblebees, and who need to be sure that

they can go back to work safely.
Immunotherapy for food allergy?
Attempts to use standard immunotherapy for food allergy have been made repeatedly, but without success.

The process of giving the injections is nerve-racking because of the constant risk of a severe

reaction. The risks prevent the dose of allergen being increased very much, so the beneficial effects

are small. While there may be some reduction insensitivity, it is not enough – or not reliable enough –

to be of any practical value.
What doctors are aiming for here, incidentally, is simply to protect against the effects of

accidentally eating a tiny amount of the food – no one is expecting that someone with peanut allergy

will be able to eat peanut butter sandwiches as a result.
Some of the new developments in immunotherapy may be useful for food allergy, as described in the next

section.
The future of immunotherapy
Many different research teams are working on ways of improving immunotherapy – making it more

effective, safer to give, and less time-consuming.
One approach involves altering the allergen, so that it only interacts with those parts of the immune

system whose job is to control allergic reactions (and therefore bring about tolerance). The changes

made to the allergen are designed to make it ‘invisible’ to the parts of the immune system that

actually attack the allergen. The idea is to inject something that can’t cause a bad reaction, and is

therefore 100% safe.
The modified allergens are called allergoids. Another term often used is peptide immunotherapy – this

describes a technique in which the allergens are chopped up into small pieces to make them safe

(allergens are proteins, and a fragment of a protein is called a peptide).
Already, researchers in Germany have made an allergoid from birch pollen that can reduce hayfever

symptoms with a series of just seven injections given before the pollen season.
Meanwhile, a research team in London is working on peptides made from cat allergen, with encouraging

results so far. In a group of asthmatics who were allergic to cats, a series of 4-10 injections, over a

period of 2-8 weeks, produced benefits in about half those treated. The researchers believe that they

can improve on this and help the majority of people with cat allergy, at least enough to survive

temporary exposure to cat allergen (when visiting cat-owning friends, for example). They hope to refine

the treatment sufficiently to enable some cat-allergic people to keep their pet, rather than finding it

a new home. This is a relatively safe treatment that might be given by a GP, rather than only by

specialists. The research team hopes the treatment will be available by about 2009.
Could this kind of technique work for food allergy? Doctors believe that it can, and a great deal of

research work is being done, in both Britain and the United States. A major focus of this effort is

peanut allergy, since this puts so many young lives at risk. Even if the research is successful, It

will be several years before such treatments become available.
Researchers are also working hard to produce standardised allergen extracts – in other words, allergen

extracts that always contain a standard amount of the allergen. The aim is not only to reduce the

number of treatment failures (which can occur if the extract does not contain enough allergen) but also

to avoid mishaps when a new vial of allergen extract is used (differences in strength, between one vial

and another, are sometimes a cause of anaphylactic reactions).
Standardisation is difficult, because the starting materials –skin particles from horses, for example,

or dust-mite droppings –are natural materials and therefore variable. Some samples contain far more of

a particular allergenic ingredient than others.
One way around this problem is to develop accurate methods of measuring the amount of allergen in the

extract. Another approach is to abandon the whole business of making extracts, and produce allergens

artificially, in a laboratory. This is done by inserting the gene for the allergen – the gene for the

Der p1 allergen of house-dust mite, for example – into bacteria. These bacteria then act as production

units, manufacturing large amounts of the allergen every day. With this high-tech approach, the exact

content of the allergen preparations can be controlled.
These high-tech allergen preparations are extremely pure, and therefore very effective – as long as the

person receiving immunotherapy really is sensitised to the particular allergen that is included.

Unfortunately, most natural allergenic materials contain two, three or even more separate allergens. In

house-dust mite droppings, for example, while Der p1 is the allergen that affects most people, there is

also an allergen called Der p2, and a few people are more sensitive to this than to Der pl.
Artificially produced allergen preparations usually include the main allergen only. For the minority of

people who are more severely allergic to one of the other allergens, this extract will not work.

Eventually this problem will no doubt be circumvented by means of more precise skin testing before

immunotherapy begins – skin tests with individual allergens, rather than with allergen extract

containing a mix of allergens.
A third approach is to change from injections to oral immunotherapy – giving the allergen extracts by

mouth. The best results are obtained when the allergen is held under the tongue for a while and then

swallowed. This is known as Sub-lingual immunotherapy or SLIT, and has become very popular in Italy and

France, where it is a common treatment for hayfever. A recent pilot trial among GPs in Britain suggests

that it may be useful, but is not a miracle cure. Overall, the group treated with SLIT had fewer

symptoms during the pollen season, but antihistamines were still needed. There is some evidence from

Italy that SLIT might reduce the likelihood of children with hayfever going on to develop asthma, and

reduce the chance of new sensitivities.
Side effects are unusual with this treatment, and those that do occur are mostly mild – itching in the

mouth, for example. The treatment is safe enough for routine use in children.
Might oral immunotherapy work for food allergy? Other Italian studies suggest that it could. The

objective of these studies is to reduce the risk to children with cow’s-milk allergy from accidental

encounters with ‘hidden milk’ in prepared food or drink. The immunotherapy treatment begins with

miniscule amounts of milk – the doctors start with a single drop diluted in water, each day for a week

– and increase the dose extremely slowly. Antihistamines are given to minimise the risk of a reaction.
The whole process requires enormous patience, but after seven months, the majority of the children

involved can tolerate some milk – between three tablespoonfuls and a small cupful each day.
This is a very encouraging study that should be repeated by doctors in Britain. Because of the risks of

anaphylaxis – which can, of course, be fatal – it does require full medical supervision, and you should

not attempt it at home. Whether this method would work for allergens other than milk is something that

nobody has yet investigated.
A great many other approaches to immunotherapy are currently being tried for food allergy. Many of the

new techniques are highly experimental, and some show great promise, but it will be many years before

they are in use.
One innovation that is closer to being in general use in the United States involves giving the anti-IgE

drug omalizumab (see p. 149) alongside immunotherapy injections. The drug maximises the benefits from

the immunotherapy, and may make the build-up stage (see p. 165) safer, by lowering the risk of

anaphylaxis. For British allergy sufferers, who cannot yet get omalizumab, and whose chances of getting

immunotherapy are vanishingly small, it may seem unkind even to mention such treatments, but we can

only hope that things will improve here in the near future. You might take some comfort from the

thought that, by the time immunotherapy is available again in Britain, there will be a whole host of

highly effective new techniques available for doctors to try.
All the methods described above are forms of specific immunotherapy – they treat an allergy to dust

mites or to grass pollen or some other specific allergen.
A far more radical and ambitious approach to immunotherapy is now the aim of some medical researchers:

blocking the tendency to allergies as a whole.The underlying idea here is to reverse the basic shift in

the immune response, from Th1 cells to Th2 cells. It is this shift to Th2 cells which produces the

allergic tendency (see pp. 11 –13).
Some interesting findings have already been made in this area, including the surprising discovery that

the balance of Th1 cells and Th2 cells can be adjusted even in people with longstanding allergies.

Inspired by discoveries about hygiene and allergy (see p. 21), British researchers have made a vaccine

containing inactivated cells of a harmless bacterium found in the soil, Mycobacterium vaccae. This is

given as a single injection just under the surface of the skin. It has been used for adult patients

with asthma, and for children with severe atopic eczema, with some improvement in both groups. If the

treatment proves as useful as the preliminary studies suggest, this could be a common treatment in a

few years’ time.