Posts Tagged ‘Cross-reactions’

When it comes to making bread and cakes, wheat has some remarkable cooking properties that nothing else

can match. Its characteristic proteins, called gluten, form very strong elastic threads. These make a

stringy dough that can be stretched and stretched as the bread rises. As a result, the bubbles of gas

given off by the yeast or baking powder are all embraced by the dough, giving an open, airy consistency

to the finished product.
Have no illusions – without wheat flour you cannot make a crispy baguette or a well-risen cottage loaf.

If you are able to eat rye, then rye flour makes a pretty good substitute, because it also contains

gluten, though not as much as wheat flour. But a gluten-free diet excludes rye too (see p. 177), and

then baking definitely becomes a challenge.
Even on a gluten-free diet, however, you can still make several perfectly edible, even delicious, types

of bread and cake. The secret, especially with bread, is to accept that the texture is going to be

different from wheat-based bread, but to add enough interesting flavours to give the finished product

its own special character. The gluten-free bread you make at home will taste vastly better than the

pale and pappy commercial substitutes – and at a fraction of the price.
Wheat-free and gluten-free bread tends not to keep as well as ordinary bread, so make a batch of small

loaves and freeze some of them. You can slice them before freezing, then extract and defrost a few

slices at a time, as needed. Bread that is not frozen should be kept in a plastic bag in the

refrigerator. Even when kept in this way, the bread gets rather dry and tough after a few days, and

will benefit from being toasted. Try spreading it with butter, margarine or solidified olive oil (see

page 182) before putting it under the grill – this revives bread far better than ordinary toasting.
Pastry-making without wheat is also a challenge (see p. 180) but cakes, biscuits and other sweet items

are much less of a
problem. As long as you accept the limitations of non-wheat flours, cakes can be made perfectly well

using gluten-free flours. With the right culinary tricks, you can even make a light fluffy sponge (see

pp. 180-81).
To thicken sauces and gravy, you can use cornflour or any other non-wheat flour.
If you have an allergy or intolerance to other foods, besides wheat, the recipes here can be adapted

accordingly. For example, commercial egg replacers (see p. 186) can be used in place of eggs, and milk

substitutes (see p. 183) can replace cow’s milk.
Wheat-free diets
This section is for people with an allergy or intolerance reaction to wheat. Those with coeliac disease

should read the section on gluten-free diets.
In devising a successful diet for yourself, you need to take account of two factors:
1 How sensitive are you? If you have a true allergy (see p. 62) to wheat, you may be very sensitive and

need to avoid even the tiniest amount of wheat. But if you are just intolerant of wheat (see pp. 74-6),

you probably won’t react to such small amounts. so you don’t need to be so careful.
2 Are you sensitive only to wheat, or do you also react to related cereals, namely rye, barley and

oats? Some people have to avoid these as well, because of cross-reactions (see p. 14).
Those who are highly sensitive to wheat and have cross-reactions to related cereals, need to follow the

same kind of diet as the most sensitive coeliacs (see Gluten-free diets). Ready-made gluten-free foods

(such as bread and biscuits) can be useful, and they should be safe for you, unless you are

ultra-sensitive.
Those who don’t have any cross-reactions to related cereals can tolerate the following:
•    rye bread and rye crackers, as long as they are 100% rye
always double-check. If you buy rye bread from a local bakery, and it is unlabelled, make sure the

staff understand that you must always have 100% rye bread. Ask them to tell you if they ever change the

recipe – and jog their memories about this from time to time.
•    beer – as long as it is brewed using barley. Most is, but watch out for German Weissbier, which

is made from wheat.
•    oatcakes, as long as they don’t contain wheat flour or bran. Check the label carefully.
Gluten-free diets
A gluten-free diet is more restrictive than a wheat-free diet, since gluten is also found in rye,

barley, triticale and spelt. All these must be carefully avoided.
At one time, this list would have included oats as well, but new research suggests that the proteins

found in oats, called avenin, are sufficiently unlike gluten to be safe for many coeliacs. If you have

coeliac disease, you must have medical approval before eating oats. Only those who are healthy and

doing well on a gluten-free diet should try oats, and they should not eat more than one small serving

(less than 50g/13/4oz) per day. It is vital that the oats are grown, harvested, transported, milled and

packaged separately from all wheat to avoid contamination. See your doctor regularly for check-ups (and

if possible a biopsy) to check that the oats are not causing problems.
Various flours are used to make gluten-free breads, including
flours derived from rice, potatoes, soya beans and buckwheat (not
a true wheat). These are sold in health-food shops, and can also
be bought by mail order. For gram flour, try Indian groceries. There
are also special gluten-free bread mixes available in both health-
food shops and pharmacies, but these almost always contain
soya, and it is best to avoid eating too much soya (see page 71).
coeliacs who are extremely sensitive to gluten, and have to
avoid all trace of it, should be very careful about ready-made food.
These are just some of the unexpected sources of gluten:
•    Thickeners and stabilisers sometimes contain traces of gluten. These additives are very widely

used in ready-made foods.
•    A number of food additives (including caramel, citric acid, dextrin, mono- and di-glycerides,

gum base, malt, malt flavouring, maltodextrin, maltose, MSG and vegetable gum) are manufactured from

wheat, barley or oats. Although the amount of gluten/avenin they contain is extremely small, it can

affect a few coeliacs.
•    Barley enzymes, used to make rice milk, some brands of soya milk, soy sauce and miso, can leave

minute traces of gluten in the finished product. Blue cheese can also contain minute traces of gluten

(see p. 174).
•    Whisky and gin – both grain-based spirits – can contain gluten. So may distilled white vinegar.

These will only affect the most sensitive coeliacs, whereas beer must be avoided by all coeliacs, since

it is made from barley.
•    Composite ingredients in ready-made food are covered by the 25% rule (see p. 174), and

frequently contain wheat.
•    Wheat flour may be used as an aid to food preparation, leaving tiny residues in the food (see

p. 174).
•    Non-wheat flour may be delivered to the factories, or transferred from one area to another,

through hoppers or vacuum tubes that have previously been used for wheat flour. Very low levels of

contamination can occur in this way, sufficient to affect those coeliacs who are extremely sensitive.

This is one problem with gluten-free foods (see below), unless they are made in dedicated gluten-free

factories.
•    Products labelled ‘gluten-free’ may not be suitable for the most sensitive coeliacs. Testing

for very small amounts of gluten is difficult, and the international standard set by the FAO/WHO (not

more than 200 parts per million) is dictated by what can be accurately measured, and therefore policed.

Many countries (e.g. Sweden and the United States) feel that the permitted level of gluten should be

lower, and have set their own standards. These higher standards can be achieved by careful control of

the production methods.
There is a great deal of useful information about gluten on the
Internet, but there is also some very misleading information on one
particular website. It is advisable to consult several different sites.
Wheat-free baking powder
Some brands of baking powder contain a little wheat flour. You can make a wheat-free version by mixing

60g (2oz) sodium bicarbonate with 125g (41/2oz) cream of tartar and 60g (2oz) of a non-wheat flour.

Sieve together very thoroughly.
Brown bread
This mixture of buckwheat and potato flour makes a light-textured loaf that also toasts well.
PREPARATION TIME: 15 minutes, plus about 1 hour rising time
COOKING TIME: about 35 minutes
MAKES: 1 large loaf
250g (9oz) buckwheat flour
250g (9oz) potato flour 1 tsp salt
1 sachet easy-blend yeast
25g (1oz) butter
1 tbsp black treacle 1 large egg, beaten
Mix the flours, salt and yeast in a large bowl and rub in the butter. Dissolve the treacle in 225ml

(8fl oz) hand-hot water. Add this and the egg to the flour, and mix to a soft dough. Transfer to a

buttered 900g (21b) loaf tin, wrap in a polythene bag and leave in a warm place for about 1 hour – or

until the mixture has risen to the top of the tin.
Bake in a preheated oven at 220°C/ 425°F/gas mark 7 for about 35 minutes until risen and firm to the

touch. Remove from the tin and tap the base – it should sound hollow. If not, return to the oven for a

further 5 minutes. Cool in the tin for 10-15 minutes.
Variations: many different kinds of flavourings can be added to this bread. Try seeds such as poppy

seeds, mustard seeds, caraway seeds and onion seeds (Indian stores usually stock these with their

spices). Sunflower seeds and sesame seeds – either plain or lightly toasted – are also good. A

combination of black olives, sun-dried tomatoes and a pinch of mixed herbs makes a Mediterranean -style

bread.
Seeded rice bread
This makes a delicious, ‘nutty’, textured loaf that is yeast-free as well as wheat-free. It toasts

quite well.
PREPARATION TIME: 30 minutes COOKING TIME: 40 minutes MAKES: 1 small loaf
150g (5′12oz) brown rice, well rinsed
100g (31,2oz) rice flour 100g (3V2oz) fine oatmeal
1 tsp wheat-free baking powder
1 tsp salt
50g (13/4oz) sunflower seeds
25g (1oz) linseed
1 large, slightly under-ripe pear. peeled, cored and coarsely grated
2 large eggs, beaten
2 tbsp vegetable oil
4 tbsp buttermilk, live natural yogurt, milk or milk substitute
Cook the rice in plenty of boiling water for 15-20 minutes until tender. Drain thoroughly and cool

slightly.
Preheat the oven to 200°C/400°F/gas mark 6.
Combine all the ingredients in a large bowl, then transfer to a well-oiled 450g (1 lb) loaf tin and

bake for about 40 minutes, until slightly risen and golden, and firm to the touch. Cool slightly, then

turn out onto a wire rack and leave until completely cold. Serve cut into thick slices.
Banana loaf
This semi-sweet bread is yeast-free as well as gluten-free. It is good for packed lunches – and it

toasts well.
PREPARATION TIME: 10 minutes COOKING TIME: about 1 hour MAKES: 1 large loaf
4 medium ripe or under-ripe bananas 300g (10′,12oz) brown rice flour, sieved 100g (3112oz) butter,

softened
2 tbsp wheat-free baking powder 2 large eggs
225ml (Bfl oz) milk or soya milk
Butter and line the base of a 900g (21b) loaf tin. Peel and cut up the bananas and place in a food

processor with the remaining ingredients. Blend thoroughly, then transfer the mixture to the prepared

tin Bake in a preheated oven at 180  350°F/gas mark 4 for about 1 hour until risen and firm to the

touch. Cool in the tin then turn out onto a wire rack and leave to cool completely.
Rich herb bread
This is useful for those who have to avolo yeast as well as wheat/gluten.
PREPARATION TIME: 20 minutes COOKING TIME: 30-40 minutes MAKES: 1 small loaf
1108 (4oz) gram or chickpea flour
1 tsp syrup or honey
2 tbsp olive oil
1 tsp salt
1 unripe pear, peeled and grated
200m1 (7fl oz) boiling water
2 eggs
V2  onion, finely chopped
fresh herbs (thyme, tarragon or marjoram)
Mix the first five ingredients, then pour on the boiling water. Separate the eggs, beat the yolks

thoroughly and add to the flour mixture when It has cooled, along with the onion and herbs. This

mixture should now be the consistency of double cream. If too thick, add a little more water.
Whisk the egg whites until they will stand in soft peaks. Carefully fold them into the flour mixture.

Pour into a well-greased loaf tin and cook at 180 - C/ 350°F/gas mark 4 for 30-40 minutes.
Seeded rice bread    Pressed prune and walnut bread
Crispy millet baps
Tasty and filling, these are popular with children. They make no pretence to be bread but are an

excellent substitute for breakfast toast or a lunchtime sandwich. They are free from yeast, milk and

eggs, as well as wheat.
PREPARATION TIME: 30 minutes COOKING TIME: about 20 minutes MAKES: about 20 small baps
225g (Boz) millet seeds
1 tsp salt
150g (5′,12oz) peanut butter (or cashew, pecan or another nut butter)
1 tsp sesame seeds, toasted until golden
oil for frying
Wash the millet and soak overnight. Wash again to remove the starch, drain and add 600ml (1 pint) water

plus the salt. Boil over a low heat for 20 minutes, or until the water is absorbed.
While still hot add the nut butter and sesame seeds. Mix together well using a potato masher to break

up the millet. Take egg-sized lumps of the mixture, roll into a ball between the palms of your hands,

then squash into a flattish shape. It is vital to do this while the mixture is still warm.
Fry the baps in oil over a low heat, for about 20 minutes, or until the outside is golden and crunchy.

(They can also be frozen, and then fried from frozen, for a quick meal.) Serve with fruit or a salad.
Savoury spiced pancakes
This variation on a traditional drop scone makes a good substitute for bread. The pancakes are

delicious served warm from the pan. When cold, they may be reheated in a moderate oven.
1008 (3112oz) gram flour
1008 (3 72oz) rice flour
1 tsp wheat-free baking powder
1 tbsp ground cumin
large pinch of salt
1 large egg
300mi (112 pt) coconut milk
vegetable oil for frying
To serve:
Skinned and chopped fresh tomato mixed with a little freshly chopped coriander, or fried mushrooms with

chopped spring onion and parsley moistened with a little crbme fraiche.
Mix the dry ingredients together in a bowl then beat in the egg and coconut milk to give a thick

batter. Set a large non-stick frying pan or griddle over medium heat. Generously oil the surface of the

pan then drop well-spaced tablespoons of the mixture into the pan.
Cook until the edges of the drop scones start to form bubbles and the base of each is golden, then

carefully turn and cook on the second side until golden. Keep warm, covered with a clean tea towel,

while you make the rest.
Serve warm, spread with butter or topped with one of the savoury mixtures.
Variations: for sweet drop scones omit the cumin and add 25g (I oz) caster sugar and either a sweet

spice such as cinnamon, or the finely grated zest of 1 lemon or orange.
Pressed prune and walnut bread
Based on a traditional Spanish recipe, this is delicious served with cheese, or as a snack on its own.
PREPARATION TIME: 10 minutes, plus overnight COOKING TIME: 45 minutes MAKES: 1 x 18cm (7in) loaf
500g (1 lb 2oz) ready-to-eat pitted prunes 100g (3%2oz) walnut or pecan halves 50g (13/4oz) brown rice

flour
1 large egg, beaten
Place all the ingredients in a bowl and mix together. Press into an oiled 18cm (7in) sandwich tin,

cover with oiled foil and cook in a preheated oven at 170°C/ 325°F/gas mark 3 for 45 minutes. Place a

heavy weight on top and leave until completely cold before unmoulding. Serve cut into thick slices

using a serrated knife.
PREPARATION TIME: 25 minutes MAKES: about 27
Walnut macaroons    Lemon surprise pudding
Millet tabbouleh
Tabbouleh is a salad from the Middle East that is traditionally made with cracked wheat. Millet makes a

very tasty wheat-free alternative. This dish can be useful for packed lunches.
PREPARATION TIME: about 40 minutes MAKES: 4-6 servings
175g (6oz) millet 7 tbsp olive oil
3 tbsp lemon juice
3 tbsp each freshly chopped mint and
flat-leaf parsley
2 spring onions, finely chopped
salt and pepper
Place the millet in a saucepan with 1 tbsp oil and cook over medium heat, stirring, for 2-3 minutes

until lightly toasted. Stir in 350ml (12fl oz) boiling water and simmer uncovered for about 20 minutes

until the water is absorbed and the millet seeds are just cooked. Transfer to a bowl, stir in the rest

of the oil and season generously. Stir in the lemon juice and fork it through the mixture. Leave to

cool, then add the herbs and spring onion and stir well.
Variations: add other finely chopped ingredients such as tomato, red pepper or dried apricots.
Wheat-free flan pastry
Make a flan as suggested below, or chill the pastry then grate it roughly over a savoury or sweet pie

filling. For a savoury pie, the grated pastry can be mixed with grated cheese.
PREPARATION TIME: 15 minutes, plus 30 minutes freezing
COOKING TIME: about 20 minutes MAKES: 1 x 20cm (8in) flan case
125g (412oz) fine cornmeal (maize flour) 50g (13/4oz) gram flour
25g (1 oz) arrowroot powder
25g (I oz) ground almonds
75g (23/4oz) butter or baking margarine 1 egg white
Mix the dry ingredients together in a bowl then rub in the butter. Mix to a soft dough with the egg

white. Press the pastry evenly into a 20cm (8in) fluted flan tin and set in the freezer for a minimum

of 30 minutes.
Preheat the oven to 200′C/400′F/gas mark 6 and cook the flan case towards the top of the oven for about

20 minutes, until lightly golden.
Variation: for sweet pastry, add 25g (I oz) caster sugar
Rich cheese biscuits
These crisp biscuits are good to serve with drinks. Store them in an airtight tin.
PREPARATION TIME: 20 minutes COOKING TIME: about 25 minutes MAKES: 20 biscuits
55g (2oz) soya flour
40g (1 V2oz) potato flour
40g (I Y2oz) rice flour
115g (4oz) butter, softened
1158 (4oz) Cheddar cheese, grated
1 large egg, separated
2 tbsp seeds such as celery or poppy
Mix the flours together in a bowl, then work in the butter, cheese and egg yolk to give a firm dough.

Roll into 20 balls. Lightly whisk the egg white and turn the balls in it until lightly coated, then dip

in the seeds to coat lightly.
Space the balls well apart on baking trays and press down firmly to flatten. Bake in a preheated oven

at 200°C/400 T/ gas mark 6 for about 25 minutes until golden. Cool slightly then transfer to a wire

rack. Leave until cold and crisp.
Whisked sponge cake
This cake’s lightness lies in the whisking. A trail of the mixture, falling from the whisks, should

remain visible for at least 30 seconds. Then it’s time to add the flour.
PREPARATION TIME: 25 minutes COOKING TIME: 25-30 minutes MAKES: 1 x 23cm (91n) cake
75g (2314oz) gram flour
50g (13/4oz) cornflour
4 large eggs
125g (4 V2oz) caster sugar
50g (13/4oz) butter, melted
To serve:
jam or lemon curd
whipped cream (optional)
caster sugar
Sift the flours together. Butter a 23cm (9in) spring-release tin and line the base with greaseproof

paper. Using a handheld electric whisk, whisk the eggs and sugar in a heatproof glass bowl over a

saucepan of simmering water for about 10 minutes until thick and mousse-like.
Fold the flour into the egg mixture in 2-3 batches until completely incorporated, then fold in the

butter.
Transfer to the prepared tin and cook in a preheated oven at 190′C/375′F/gas mark 5 for about 25

minutes until risen and golden. Cool slightly then remove from the tin and cool on a wire rack. When

cold, split and fill with jam or lemon curd, and whipped cream if wished. Dust with caster sugar.
Walnut macaroons
These biscuits are good with coffee. Store in an airtight container. If you want, only decorate half of

them with walnut halves, then sandwich together with the other halves using coffee-, chocolate- or

orange-butter cream, or whipped cream. Do this just before serving.
PREPARATION TIME: 15 minutes COOKING TIME: about 45 minutes MAKES: 24
rice paper
2 egg whites
100g (3112oz) golden icing sugar
1008 (3 Y2 oz) walnut pieces, finely
chopped
grated zest and juice of 112 small unwaxed
lemon (if waxed, wash thoroughly in
hot water)
24 walnut halves
Line a large baking tray with rice paper. Whisk the egg whites in a heatproof glass bowl until stiff.

Stir in the icing sugar, chopped walnuts, lemon zest and juice, and stir over a saucepan of simmering
water for about 10 minutes until the mixture is slightly stiffened. Drop well-spaced spoonfuls of the

mixture onto the rice paper and top each with a walnut half.
Bake in a preheated oven at I 50′C/300′F/gas mark 2 for about 45 minutes. They should be risen but

still slightly chewy. Cool on the tray, then trim away the excess rice paper.
Lemon surprise pudding
The surprise is in the two layers. You end up with a creamy lemon sauce topped with a delicate sponge.
PREPARATION TIME: 20 minutes COOKING TIME: about 45 minutes MAKES: 4-6 servings
50g (1314oz) butter
125g (4 Y2oz) caster sugar
2 large eggs, separated
25g (1 oz) cornflour, sieved
25g (1oz) fine cornmeal (maize flour), sieved
finely grated zest and juice of 2 unwaxed lemons (if waxed, wash thoroughly in hot water)
250m1 (9fl oz) milk To serve:
icing sugar
Cream the butter and sugar with 1 tbsp hot water until pale and fluffy. Beat in the egg yolks followed

by the flours. Slowly stir in the lemon zest and juice, and then the milk. The mixture may appear to

have curdled but this is normal.
Whisk the egg whites to form soft peaks, then fold into the lemon mixture. Transfer to a 1 litre (13/4

pint) ovenproof dish and set in a roasting tin. Pour hot water from a kettle around the dish and cook

in a preheated oven at 180°C/350°F/gas mark 4 for about 45 minutes, until risen and just firm to the

touch. Dust with icing sugar and serve immediately.
Apricot and apple Eve’s pudding
This wheat-free Eve’s pudding can be varied by changing the fruit. Try peaches, strawberries or

blackberries instead of the apricots.
PREPARATION TIME: 30 minutes COOKING TIME: about 1 hour MAKES: 4-6 servings
400g can of apricot halves in juice
2 medium cooking apples, peeled and thickly sliced
50g (1314oz) caster sugar
Topping:
125g (472oz) butter, softened
125g (4 Y2oz) caster sugar
2 large eggs
125g (4V2oz) ground almonds mixed with
1 tsp wheat-free baking powder
50g (1 31ioz) flaked almonds
To serve:
pouring cream or whipped cream
Pour the juice from the can of apricots into a saucepan, add the apple and sugar and cook gently for

about 5 minutes, until the apple is softened. Remove from the heat and stir in the apricots. Transfer

to a 1 Iltre (13/4 pint) ovenproof dish.
In a separate bowl, cream the butter and sugar together until pale and fluffy then beat in the eggs one

at a time. Fold in the ground almonds and baking powder. Spread the almond mixture over the fruit and

sprinkle with flaked almonds. Cook in a preheated oven at 180°C/ 350°F/gas mark 4 for about 1 hour

until risen and golden and just firm to the touch. Serve with pouring cream or whipped cream.

Allergens and irritants at work
Some workplaces have very high concentrations of allergens in the air, especially if proper safety procedures are not being followed. Occupational allergies can begin with symptoms in the nose, such as sneezing, blockage or constant streaming (allergic rhinitis). You may also suffer with itchy or watery eyes (conjunctivitis), a cough, sweating and a feverish feeling. Alternatively, direct contact with the allergen can produce a skin rash (dermatitis) or itchiness and swelling (contact urticaria/nettle rash and angioedema).
If you work somewhere with an allergy risk (see pp. 133-4), be vigilant for such symptoms and see your doctor immediately. These symptoms can be the forerunners of occupational asthma, which is a serious and potentially irreversible problem. Some allergens, such as latex, can even produce anaphylactic shock (a life-threatening allergic collapse).
Skin-prick tests (see p. 91) can show if you have an allergy to a substance encountered at work.
Acting promptly gives you the best possible chance of recovery and is vital if you have occupational asthma. Only if exposure to the allergen stops promptly do you have a good chance of shaking off the asthma. See your doctor as soon as possible and ask for a referral to a chest specialist, so that a definite diagnosis can be made. This is essential if you are going to make a claim for compensation.
Far too many people with occupational asthma are just sent off with an inhaler when they first see their doctor. By delaying the moment when work is identified as the source of the problem, and the exposure to the allergen is stopped, drug treatment can turn occupational asthma into a disabling lifelong problem. Although drugs can be helpful in speeding your recovery once exposure to the allergen
Latex allergy
Sensitisation to latex usually occurs at work (see pp. 133-4), or as a result of having many surgical operations. But latex allergy sometimes occurs in allergy-prone people even though they don’t work in a high-risk job and haven’t had many operations. Some doctors think that if a child with severe allergies needs surgery, this should be done in latex-free conditions, even though the child has no allergy to latex, because of the risk that the operation will sensitise.
Latex can cause either contact dermatitis (see p. 55) or a Type I allergy, whose symptoms can include urticaria, asthma and anaphylaxis. Latex allergy often goes undiagnosed. Once sensitised, you may react to balloons, elastic bands, condoms and household gloves. Latex in the air,
due to powdered latex gloves being used, can be a hazard for someone who is highly sensitive, as can latex traces in food (see box on p. 175). Medical treatment may be problematic (see p. 98 and box on p. 249). Cross-reactions to certain foods can occur (see p. 15 and p. 51).
For those avoiding latex, there are non-latex gloves (see p. 57), and non-latex condoms. Immunotherapy (see pp. 164-9) may be useful in severe cases: it can reduce sensitivity and eliminate cross-reactions to foods.
Other hazards
This article (pp. 132-5) deals mainly with allergens at work, that is, substances which provoke classical allergies (Type I reactions). In addition, there are skin irritants and antigens in workplaces which can provoke contact dermatitis (see p. 56) or contact urticaria (see p.50).
Some of the most dangerous workplace substances are those that bring on asthma but are not allergens. These are usually called low-molecular-weight asthmagens. The most notorious of these are platinum salts, isocyanates (used in cement, in the manufacture of foam, plastics and varnishes, and for spray-painting cars, aeroplanes and boats), colophony (used as a solder in electronics), glutaraldehyde (used in hospitals for sterilisation procedures), and persulphate (used in hairdressing). Powerful respiratory equipment, supplying air from outside the area (see p. 135) is needed if you work with some of these substances, e.g. isocyanates for spray-painting cars.
has ended, they should not be seen as a way of allowing you to go on working with the offending allergen or asthmagen.
If it seems plausible that your allergies or your asthma are related to your work, your doctor should be able to give you a sickness certificate, so that you can have some time away from the workplace, to see if you recover. The medical service at your workplace may be better at diagnosing occupational asthma than your own doctor, but be cautious. In some workplaces they do operate as they should and offer genuinely confidential treatment. But there have also been cases of information being passed to the management, and workers with the early signs of occupational allergies and/or asthma being dismissed on a pretext, or made redundant, to avoid a possible compensation claim. Most occupational health services claim to be independent, but they actually have to earn the trust of the workforce. Before you make any move, ask your colleagues for their views, especially those who have worked there for many years.
Choosing a job
If you have any tendency to allergies, or come from an allergy-prone family, you should be very choosy about where you work. Try to avoid workplaces where there is heavy exposure to allergens, especially airborne allergens which can provoke asthma:
• Bakeries and flour mills, where the allergens concerned may be wheat proteins in the flour, or enzymes added to the flour mix. These allergies can take years to begin.
• Other food-processing works, particularly those dealing with tea, soyabeans, other beans (e.g. gram flour), shellfish and fish (especially if automated gutting machines are used without adequate ventilation). Food preparation and sandwich-making can cause contact urticaria, if there is prolonged contact with a particular foodstuff (e.g. tomatoes).
• Farms, docks and cotton mills – or any other workplace generating dust from plant products. On farms, it is the dust from grain and hay that is often responsible, although mould spores (see p. 121) can also be the culprit. Allergies to mites (found in hay, grain and flour) sometimes occur and eczema is the most common symptom – often called simply ‘grain itch’.
• Saw mills and joineries, because of the wood dust, especially that from hardwoods and from red cedar (Thuja plicata).
• Paper recycling plants, if there is a lot of paper dust in the air.
• Detergent and pharmaceutical factories handling enzymes – these are added to ‘biological’ washing powders and are potential allergens. The risks are less these days, as the enzymes are in granule form rather than powder.
• Factories processing natural products such as psyllium or ispaghula, which are used as laxatives. Anyone who has been sensitised should avoid taking medicines containing the offending substance in the future, because these can sometimes provoke a dangerous anaphylactic reaction.
• Hospitals, clinics and dental surgeries, mainly due to latex rubber, used in gloves and equipment. Although nursing staff and surgeons are most susceptible, other staff including hospital administrative workers can occasionally be affected. Fears about the spread of the HIV virus has led to a huge increase in the use of latex gloves in medicine and dentistry, and a consequent epidemic of latex allergy. The main problem is with powdered latex gloves, which release 15,000 times as much allergen into the air as unpowdered gloves. Unpowdered, low-allergen gloves greatly reduce the risk of latex allergy developing, and non-latex gloves are even better. There are moves to ban the import of powdered latex gloves into Britain. They are already being phased out in hospitals and other medical facilities, but progress is slow in some areas.
• Other workplaces where powdered latex gloves are used, including
Making the workplace safe for everyone
Note that these choices about employment are for the individual employees to make for their own protection - an employer cannot refuse to take anyone on because they have allergies or come from an atopic (allergy-prone) family.
The reasoning behind this is that the workplace should be safe for everyone, as far as possible. As many as one in three of the population may be susceptible to allergies, and it is clearly wrong to bar all such people from major industries. Current thinking, in most countries, is that the focus should be on getting allergens and asthmagens out of the air, not keeping the more vulnerable workers out of the workplace.
hairdressers, dental surgeries, pathology laboratories and police stations. Construction workers wearing rubber gloves are also at risk. Someone who has been sensitised by powdered latex gloves may then react to other items (see box on p.132). Those severely affected can have great problems in daily life and with medical treatment, so anyone with a strong tendency to allergy should strenuously avoid becoming sensitised.
• Factories making or using rubber items may also expose workers to the risk of latex allergy. Anything made by the ‘dipping method’ (e.g. balloons, condoms, elastic bands and gloves) is highly allergenic. Moulded rubber items, such as tyres, are much less of a problem. Neoprene and other synthetic rubber items are not allergenic.
• Chiropody and podiatry clinics, where there is a risk of allergic reactions to the fungus that causes athlete’s foot. It is inhaled on skin flakes from the patients’ feet.
• Laboratories and other workplaces where animals are kept. In the case of mice, rats and other rodents, the allergen is found in the animals’ urine, and becomes airborne as the urine dries. Insects and spiders (e.g, those reared for biological pest control), are also allergenic due to small airborne particles from their bodies. Those working closely with bees (either honeybees or bumblebees, now reared for pollinating glasshouse crops) are liable to be stung frequently, and this can lead to sting allergy (see pp. 60-61).
• Hairdressing salons, where many different items are used that are potentially allergenic, including latex gloves (see above), permanent-wave solutions and henna. The risks of contact dermatitis are also high (see p. 55).
• Greenhouses, where the enclosed conditions can lead to high levels of allergens from plants, moulds and insect pests. There may also be exposure to pesticide sprays or their residues, which can greatly aggravate any underlying tendency to allergies.
If you have ever suffered from atopic eczema, work situations that can bring on contact dermatitis should also be avoided (see p. 55).
Taking a risky job
If circumstances force you to take a job with an allergy risk, observe all the safety procedures that are in place, and where you have the option of turning on extractor fans, wearing protective gear, or simply opening doors and windows, always do so. If the safety procedures seem inadequate, talk to your trade union Safety Representative, or the local Health and Safety Executive which can run a check on safety procedures in your workplace. This will be presented to the employer as a routine check, so they need never know that a member of the workforce has contacted the HSE.
Whatever you do, if you are in a risky job, don’t smoke. At a salmon processing plant in Scotland, 40% of the smokers developed allergies (resulting in asthma) to the fish allergens in the spray from the fish-gutting machine. Non-smokers - who formed the overwhelming majority of the workers - were not affected at all. In United States cotton mills, smokers are affected by levels of cotton dust in the air that are legally defined as ’safe’, while nonsmokers remain unaffected.
Passive smoking at work is also an important issue. A recent US study showed that non-smokers were more likely to develop asthma if they worked alongside a smoker. Your employer has a duty to provide you with clean air. This includes ensuring that other employees do not impose their cigarette smoke on you.
Respiratory equipment
Where respiratory equipment is needed, your employer must provide this, and it must be the right equipment for the job. It should be inspected, tested, cleaned and repaired after each use, and filters should be replaced regularly. All this is your employer’s responsibility, but check that it is being done, and always look the mask over before you put it on.
Two different types of respiratory equipment are currently in use:
• Those that give you a supply of air from outside the work area, either from a compressed-air cylinder, or via an air-hose (airline) supplied with fresh air. In Britain these are called breathing apparatus.
• Those that use the surrounding air but filter it to remove allergens and asthmagens. In Britain these are called respirators. (In some countries this term describes any kind of respiratory equipment.) Ordinary respirators may pose problems for some asthmatics because they cannot breathe in strongly enough to draw sufficient air through the filter. Powered respirators can be the answer: they have a battery-powered unit to help with pulling in the air.
There are government regulations concerning the type of equipment required for each type of allergen and asthmagen. Large companies generally follow these regulations, but small businesses, such as local sawmills, joineries and car-repainting workshops, may not even know about them.
Any respiratory equipment that has a face mask must form a tight seal with your face. Facial hair will prevent this, and so will stubble, so shave carefully. Faces vary enormously in shape, and if your face mask does not fit, ask for a different type of mask or a different type of respiratory equipment. Persist until you get one that’s right for you.
Carry out a ‘fit check’ each and every time you wear the mask. For example, with respirators, you can check the fit by covering the air intake completely with your hand and breathing in sharply: if the mask fits properly, it should collapse onto your face, and remain stuck to your face for several seconds. Look at the manufacturer’s instruction booklet as there may be a specific fit check recommended for the equipment you are using.
If there is any difficulty in breathing through the respiratory equipment, the replaceable filter cartridge or the equipment itself should be replaced. You should also take action immediately if you can smell the substance being handled – but never rely on this as a danger sign, because an extremely small amount, way beyond the detection capacity of the human nose, may be very damaging indeed to your health.
Keep your mask on throughout the work period. If you find this impossible, talk to your employer or
line manager about getting a different kind of respiratory equipment – a powered device, for example, that assists the inflow of air.
No form of respiratory equipment provides complete protection against allergens and asthmagens: there is always the chance of some small amount getting through. This is why respiratory equipment should not be used by those who have already developed occupational asthma but want to stay in their job.
Those who really cannot change jobs (e.g, farmers) are sometimes able to use a powered respirator helmet, which allows them to go on working despite the allergen. But this is not an ideal solution from a purely health point of view. Farmers can also improve matters, where moulds are the source of allergens, by keeping all harvested crops dry and thoroughly ventilated.
A lasting problem
As long as you catch the problem early, and are no longer anywhere near the allergen, your symptoms should disappear completely, but remember that you may still be highly sensitive to the allergen, even years afterwards. For a year or two at least, avoid contact with it again, even in tiny amounts. If someone else in your family works at the same place, they may bring home traces of the allergen on their clothes and hair: ask them to leave their workclothes outside the house and shower on arriving home.
With occupational allergies to airborne food particles, it is possible that the affected individual will later react to the same food when eaten. Experiment very cautiously, especially if the allergen is fish or shellfish.
The allergy may persist long after the job has ended. In one case, doctors found that a woman who had developed ‘baker’s asthma’, while working briefly in a bakery when young, was still allergic to the enzyme additive in bread 20 years later. She suffered an asthma attack whenever she ate bread.

Bees, wasps and other stinging insects

`Know your enemy’ is always a good motto, but particularly for those with insect-sting allergy. Being allergic to wasps or hornets, for example, is enough of a problem without panicking every time you encounter a hoverfly as well. If your reaction to this is ‘What’s a hoverfly?’ then you need a good field guide or a friend who knows a little about natural history. These common insects have yellow-and-black stripes to mimic those of wasps, giving them some protection against predatory birds. They fool a lot of people as well as birds, but it isn’t difficult to tell the two apart — hoverflies are a different shape from wasps, hold their wings differently at rest, and fly in a completely different way (for one thing they hover, unlike wasps). Being able to tell one from the other will make life much more relaxing.
If you did not see the insect that stung you, ask the doctor which skin tests came up positive (see p. 61), and use a field guide to check exactly what the insect(s) looks like.
As well as knowing what your problem insect looks like, you need to know a little about its habits and tastes.
These are the general characteristics of stinging insects that you need to know about:
• The most dangerous thing you can do is to disturb the nest – all stinging insects go into attack mode when this happens. If there is a nest in or around your house, call in a pest control expert to destroy it. Never tackle this job yourself, nor allow anyone else to do it while you are in the vicinity.
• If you think there may be an insect nest in or around your house, call in a pest control expert to do a survey. Regular annual checkups of your property are advisable if insects have nested before.
• Insect repellent works only for biting insects, such as mosquitoes. It does not repel wasps, bees or other stinging insects.
• Insecticide spray can be useful, but make sure the insect is really dead before you touch it. A groggy poisoned insect may well sting.
• A small but thick blanket can be useful for catching bees or wasps that have flown into cars. Don’t try to do this yourself unless there is no alternative. Ask a passer-by to help you if you are alone.
• Always stay as calm as possible.
Wasps and hornets (vespids)
• If you react to one species of vespid, you may well have a cross-reaction to other species in this group, so take care.
• Wasps like sweet foods (e.g. jam, honey, cakes) and you should avoid taking these on picnics. They will also crawl into open cans of beer or soft drinks. Never ever drink from the can, as you can get a mouthful of cross wasp with your drink.
• In spring and early summer, wasps collect protein-rich food for their young, and may be attracted to meat. If eating outdoors, as far as possible keep food covered.
• Wasps come to fallen fruit in the autumn. They get very sluggish and bad-tempered late in the year, and will sting with little provocation. They may crawl into crevices or hollow logs as winter approaches. Be very careful about picking up fruit or dead leaves, or working in the garden –always wear thick gloves.
• Wasps are often on the ground, especially in late summer and autumn. Wear shoes and socks for protection. If working outside where there may be wasps, long trousers and long-sleeved shirts are also advisable.
• Rubbish bins and litter bins are also very attractive to wasps. Make sure your own bin has a tightly fitting lid, and that no rubbish accumulates around it. Ask neighbours to do the same. Keep away from litter bins, and from picnic sites, orchards and tea gardens, all of which are havens for wasps.
Cross-reactions between insect stings
There are cross-reactions between the venoms of wasps, hornets and related insects (vespids), so if you are allergic to one, you may react to another. Cross-reactions are very unlikely between bee and wasp venoms.
Honeybees and bumblebees have very similar venom and these cross-react (but honeybee immunotherapy does not work for bumblebee allergy – see p. 168). Surprisingly, there is some cross-reaction between honeybee venom and snake venom.
The usual suspects
Wasps (yellow-jackets in the United States), hornets and bees are the most common source of allergic reactions worldwide. Locally, there are allergic reactions to various other stinging or biting animals. Fire ants are a particular problem in the southeastern United States. Hopper ants are a cause of anaphylaxis in Australia, and allergy to leech bites has been reported from Tasmania. A few people are allergic to the kissing bugs (Triatoma spp.) – also called cone-noses, ‘big bed bugs’ or ‘Mexican bed bugs’ – that are found in South and Central America, as well as rural areas of North America. These large insects creep into beds and bite painlessly, by night. In urban areas of Italy, where large numbers of pigeons live in some old buildings, pigeon ticks that find their way indoors have sometimes caused anaphylactic shock by biting during the night. Localised reactions to earlier bites had occurred in all cases.
Honeybees and bumblebees
• When it stings, a bee loses part of itself – the stinger and venom sac – and therefore dies. So stinging is very much a last resort. Most honeybees are not aggressive, and only sting if their nest is attacked, or if they are threatened when feeding.
• Bees feed on nectar from flowers. They may be attracted by brightly coloured clothes, especially red, orange and yellow, and flower-prints, mistaking these for flowers. Wearing dull colours is advised.
• Some perfumes, shampoos and scented cosmetics or lotions may also attract bees. If bees do approach you, never swat at them, and don’t panic. The best thing is to brush them away very gently.
• Bees often feed on clover, which grows in lawns and other grassy places, and it is easy to tread on them in this situation. Walking barefoot outside is therefore dangerous.
• Bees are attracted by water, including swimming pools and paddling pools.
• Although large, bumblebees are also very placid and rarely sting.
• Swarming bees are dangerous because they have the queen with them. If you see a swarm, keep well away.
Africanised honeybees
If travelling abroad, you should remember that Africanised honeybees – found in South and Central America, Texas, Arizona and parts of California – will sting with much less provocation than ordinary bees.
They are hybrids between domestic honeybees and an aggressive variety of wild African bee mistakenly introduced to South America. While they are much more pugnacious than ordinary bees, Africanised honeybees are only intent on defending their hive, and do not maliciously hunt people down as some horror movies have implied! They inject slightly less venom with each sting than a normal bee, but multiple stings are more likely because more than one bee is usually involved.