Is it life-long?
Peanut allergy was once thought to be life-long in all cases. But recently it has been shown that about 20 per cent of young children grow out of their peanut allergy. Any five-year-old who has been free of peanut allergy symptoms for more than a year may possibly have outgrown the allergy. The child can be referred to a specialist allergy centre for “challenge testing” – in which peanuts are introduced to the child in a controlled way.

Teenagers
Teenagers and young adults may be more at risk of life-threatening reactions than younger children. But their allergies can be well managed so long as they always carry prescribed medication, learn how to use it, and are extremely vigilant when food is around. A guidance booklet for allergic teenagers is available free from the Anaphylaxis Campaign.

Avoiding peanuts and tree nuts
Peanuts can turn up under the names groundnuts, earth nuts and monkey nuts. People allergic to almonds should avoid almond essence.

Roasting and heat treatment do not reduce the allergenicity of peanuts or tree nuts. In fact laboratory experiments have suggested that roasting and heating peanuts (but not boiling) may increase their allergenicity. There have been no studies involving human subjects so our advice is to avoid all forms of peanut.

It is important to read food labels thoroughly, even if you are buying a product you have eaten before. Recipes do sometimes change. Check both the inner and outer wrapping of multi packs.

Foods most likely to contain peanuts or tree nuts include:

• Cakes, biscuits, pastries, ice cream, desserts.

• Cereal bars, confectionery.

• Vegetarian products such as veggie burgers.

• Salads and salad dressings.

• Satay sauce, curries, Chinese, Thai or Indonesian dishes.

• Marzipan and praline (confectionery products made with nuts).

• Salad dressings may contain unrefined nut oils.

The above list is not exhaustive.

Foods sold in restaurants and other catering outlets, or at in-store bakery and delicatessen counters, are generally unlabelled and so pose a particular problem. It’s important to be direct with staff, pointing out the seriousness of the allergy. If staff cannot guarantee that any dish is safe, it is best to eat elsewhere.

Other legumes
Peanuts (arachis hypogaea) are actually legumes. A small percentage of people with peanut allergy react to other legumes, such as peas, beans and lentils. Care is needed, but most will find they can tolerate these other legumes without problems.

More commonly, people with peanut allergy react to tree nuts. Many allergy experts advise peanut-allergic patients to avoid tree nuts, and vice versa.

Airline travel
People with peanut allergy often express concern that they may have a reaction during air travel, caused by the smell of the free peanut snacks distributed to passengers. We believe this to be an unlikely cause of symptoms for the vast majority of people and – when they do occur – they are likely to be mild. But please be guided by your doctor or consultant, and your allergy history. If you believe you may react in this way, it would be sensible to seek a peanut-free flight by contacting the airline well in advance.

The most likely cause of reactions in flight is through eating peanuts or nuts present in airline food. This is solved by playing safe and taking your own food on the plane. The second most likely cause is skin contact. If a passenger handling peanuts has touched the fold-down tray or another surface, there is a risk that a subsequent, allergic passenger may touch the same surface, possibly transferring peanut allergen to the face or mouth. To minimise the risk, you can always take “wet wipes” to clean surfaces.

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Sesame seeds

Sesame allergy is fairly common in some countries and it would appear to be on the increase in the UK. Occasionally reactions are severe. Even when these are mild or moderate, it must be assumed that a future reaction may be severe and medical advice should be sought in all cases.

Sesame is often used for flavouring and decorative purposes in foods. People who are allergic to sesame must seek to avoid it completely, as even a tiny amount may trigger a severe reaction.

Heating does not destroy the allergenicity of sesame.

Dishes containing sesame include: tahini, gomashio, hummus and halvah. Chinese stir fry oils sometimes contain sesame oil. Sometimes it is to be found in Aqua Libra.

People have also reported allergic reactions to vegeburgers, breadsticks, burger baps, cocktail biscuits, Middle Eastern foods, Chinese and Japanese foods, stir fry vegetables and health food snacks containing sesame.
Sesame oil should be regarded as extremely risky because it is almost certain that it will be unrefined, and therefore contain the allergenic proteins that trigger allergic reactions.

Bread and other products bought from in-store bakeries must also be viewed as suspect because these may be contaminated by sesame seeds from other bread.

Sesame is sometimes used in cosmetics and other personal care products and in such cases may be labelled under the Latin name sesamum indicum. Sesame oil may occasionally be present in pharmaceuticals. Always ask your pharmacist to obtain full ingredients of any prescribed medicine.

Allergy to sesame needs to be treated as seriously as peanut allergy. Indeed many people with sesame allergy are also allergic to nuts. Nevertheless, people affected can be assured that with proper management, the risks will be minimal. Central to any management strategy are proper medical advice, care and vigilance at all times and a commitment by the patient to carry prescribed medication everywhere.

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Egg allergy

Egg allergy - common among children - is usually mild. But in rare cases egg can trigger anaphylaxis. Food labels must be thoroughly scrutinised for products containing egg or albumen.

The emulsifier known as lecithin can be derived from egg, although in practice this is uncommon. If you in doubt about any product, it is best to contact the retailer or manufacturer.

Some egg-allergic children can eat well-cooked egg (in cake, for example) without any ill effects - but not raw or lightly cooked egg. Others are allergic even to egg which has been well cooked. People who are fine with cooked egg are more likely to grow out of egg allergy.

A lot of fresh pasta contains egg, but you will certainly be able to find a dried pasta that is egg-free. Some varieties may occasionally carry a very small risk of cross-contamination with egg. Check with individual companies to identify the safe ones.

Under new European legislation, manufacturers and retailers must always label major allergens (including egg) wherever they appear in pre-packed food. This improved labelling has already begun, but food companies have until November 2005 to comply.

Some supermarkets produce lists of their own-brand products free from egg. Many people find these invaluable.

The MMR injection is normally cultured on egg. Anaphylactic reactions to the MMR have been reported, but they are very rare. In any case, it's probable that in those instances, a component other than egg was responsible. Any child who has a severe allergic problem, irrespective of whether this is due to egg or not, should at least be reviewed by a paediatrician in order to consider whether the immunisation should be administered in a controlled environment.

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Cow’s milk allergy

The term cow’s milk allergy is generally used to describe reactions generated by the immune system. This is how the term will be used here. Non immune reactions are normally classified as cow’s milk intolerance.

Cow’s milk allergy is common in infants and very young children. It rarely develops after one year of age and the onset is closely related to the introduction of cow’s milk based infant formula. The prevalence is estimated to be as high as two per cent among children under a year old. Fortunately about half outgrow their allergy by one year, and most children have outgrown it by the age of three.

However, cow’s milk allergy may occasionally be lifelong and severe.

Symptoms of milk allergy
In early infancy, symptoms are usually tummy pain and vomiting. In a small number of infants there is nettle rash, swelling of the face, eczema and respiratory symptoms including asthma.

As the infant gets older, typical allergic reactions to milk include rash, hives and redness around the mouth, which can spread all over the body, runny nose, sneezing and itchy watery eyes, coughing, choking, gagging, wheezing and trouble breathing, abdominal cramps, vomiting and diarrhoea. The reaction can stop at any stage or develop into anaphylaxis (a serious allergic reaction that affects a number of body organs).

Severe milk allergy
In severe cases, an allergic reaction to milk can develop into anaphylaxis with minute amounts. Strict avoidance of all traces of milk and all its derivatives is the only way to deal with this type of allergy. Some people choose to keep milk products out of the house. Emergency adrenaline (epinephrine) should be prescribed and kept within close proximity at all times.

Very mild milk allergy
Small amounts of processed dairy products (e.g. yoghurt and cheese) can be tolerated. The child is likely to outgrow milk allergy at an early age.

Mild to moderate milk allergy
Small traces of milk products in cooked goods can be eaten without causing a reaction. Lactose is usually tolerated but avoid milk, cream, cheese, yoghurt and ice cream.

Reactions through touch and smell
A food does not have to be eaten to cause a reaction, although eating it causes more severe reactions. Hives can occur on skin contact with milk. If food gets into the wet surfaces (e.g. through a cut in the skin, on the lips or in the eye) severe reactions can occur.

Inhaled cow’s milk protein, such as from the cheese on a pizza, can cause allergic reactions. These are not normally severe unless present in extremely high concentrations.

Avoidance of milk
Degrees of avoidance will depend on the individual and the severity of the milk allergy. Many people need to avoid milk and dairy but can cope with trace amounts in cooked goods (e.g. cakes, biscuits and pies).

Milk can turn up unexpectedly in foods so it is important to check food labels every time you shop – even if you have bought a product before. Recipes do sometimes change.

The 25 per cent rule governing compound ingredients has now been amended under European legislation. This means that food companies have to declare major allergens, including milk, even when they appear in minute quantities. They have until November 2005 to comply. If you are in any doubt about a product, call the manufacturer or retailer.

Lactose does not normally contain the proteins responsible for causing reactions, but there is a risk of contamination with milk protein. People with very severe milk allergy may be wise to avoid anything with lactose in it.

Medicines
Some medicines contain milk products so check with the prescribing doctor or with the pharmacist when collecting your prescription.

Some tablets are manufactured with the aid of lactose. As stated above, lactose does not normally contain the proteins responsible for causing reactions, but could cause problems for people whose milk allergy is very severe.

Treating symptoms
Most people with milk allergy find that antihistamines (e.g. Piriton) are usually sufficient to treat their symptoms. However if you have breathing difficulties or are at risk of anaphylaxis, then adrenaline (epinephrine) should be carried at all times (e.g. EpiPen or Anapen). These injectors are very easy to use and designed for self-administration.

Alternatives to milk
Soya milk formulae are sometimes recommended for children who are allergic to cow’s milk. However, some milk-allergic children react to soya.

Goat’s milk and sheep’s milk are not suitable alternatives to cow’s milk as they share similar proteins with cow’s milk that could result in cross-reactivity.

Most health professionals recommend special casein hydrolysed formulae (e.g. Nutramigen or Pregestimil). These are made from cow’s milk that is treated to change the proteins. A few milk allergic children react to them and need an elemental formula called Neocate.

Terms indicating the presence of cow’s milk
Apart from the obvious ingredients to avoid (such as milk, cream and dairy) watch out for the following:

• Butter, butter fat, buttermilk, butterfat, butter oil.
• Casein, whey.
• Sodium caseinate and calcium caseinate.
• Cheese, yoghurt, ghee.
• Ice cream.

Cow’s milk intolerance
Milk intolerance is different to milk allergy and does not involve the immune system. There may be delayed gastro-intestinal symptoms, such as vomiting, diarrhoea and colic. These symptoms can develop over hours or days after ingesting a modest amount of cow’s milk (over 120mls or 4oz). Allergy testing is not effective for milk intolerance. Antihistamines do not work either. Strict milk avoidance is not necessary, and traces in baking can be safely eaten.

Lactase deficiency
People who are allergic to milk react to the milk protein and not to the milk sugar (lactose). Lactase deficiency is quite different and caused by the lack of the enzyme lactase, which is needed to digest lactose.

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Shellfish and fish allergy

Adverse reactions to shellfish are rare in young children, and are usually not seen until the teenage years or adulthood. This may be a reflection of the fact that shellfish is not normally a part of the diet of young children.
Allergy to fish - such as cod and other white fish - may begin in childhood and is likely to be lifelong. Allergies to shellfish or fish are potentially serious and there may be a rapid onset of symptoms. A GP's advice should be sought in all cases and a referral made to see an allergy specialist. Patients known to be at risk may be prescribed auto-injectors containing adrenaline (also known as epinephrine).

Someone who reacts to one type of fish - even if the symptoms are mild - might be advised to play safe and eliminate all fish from their diet. This is partly because they may react to another type of fish, but also because of the high risk of cross-contamination among different types of fish (e.g. at fish markets or on fish counters).

This also applies to shellfish. People allergic to one type of shellfish are often advised to avoid all shellfish.

Different types of shellfish
Biologically speaking, shellfish are aquatic invertebrates rather than fish. They can be divided into four main groups:

Crustaceans
(e.g. crab, lobster, crayfish, shrimp, prawn)

Molluscs:
(a) Bivalves (e.g. mussels, oysters, scallops, clams)
(b) Gastropods (e.g. limpets, periwinkles, snails)
(c) Cephalopods (e.g. squid, cuttlefish, octopus)

People who have reacted to one type of shellfish (e.g. crab) are likely to react to other members of the same group (in this case, other crustaceans). If you react to crab, avoid that and the rest of the crustacean group. If you react to squid, avoid that and the rest of the cephalopod group. Shellfish from the other groups may not necessarily present a problem, although they may do for some people. It is advisable to avoid them anyway. A special reason for being cautious is that there is a relatively high risk of cross-contamination among different types of seafood.
Kosher food is shellfish-free. Always read the labels and check with food companies if you are unsure.

Should people with shellfish allergy avoid fish, and vice versa?
Fish and shellfish are biologically distinct. People who are shellfish-allergic may be able to eat fish, and vice versa - unless they have both allergies. But as stated above, be aware of the risk of cross contamination in restaurants, markets and open fish counters. If the same pair of tongs is used to handle different types of fish and shellfish, or if you suspect one type of fish or shellfish may have spilled over and had contact with another, you should avoid buying or consuming.

People have been known to go into anaphylactic shock after breathing in airborne particles of shellfish or fish allergen in open fish markets.

Avoiding shellfish and fish in restaurants
In restaurants, inform staff of your allergy. Find out what your food is fried in, and whether the oil has been used for anything else. Check the ingredients of all stocks and soups. Ideally, your companions should avoid eating fish/shellfish in your presence, as there is a small risk that breathing in the cooked food may cause a reaction.

Pre-packaged foods
As they are relatively expensive, shellfish and fish are rarely an undeclared or unexpected ingredient in pre-packaged foods. Always check the label for the type of shellfish/fish to which you are allergic. Some supermarkets (e.g. Sainsbury's) will have a "CONTAINS" bar, which will indicate the presence of fish and shellfish, but policies vary from store to store and brand to brand. Be vigilant when choosing stocks, soups and highly processed foods, which may contain shellfish or fish extract to add flavour.

Shellfish and fish allergy: dishes to look out for
Dishes to look out for include paella, bouillabaisse, gumbo (a Tex Mex dish), frito misto (a mixed fried fish dish from the Mediterranean coast), and fruits de mer (seafood). Oriental food tends to contain lots of different kinds of fish at once, and chopped pieces can be difficult to spot.

Surimi (a processed seafood product) is usually made from white fish but may contain shellfish extract. Surimi can be present in processed foods such as pizza toppings.

Caesar salad dressing normally contains anchovies. Worcestershire sauce may.

Caponata, a traditional sweet and sour Sicilian relish, can contain anchovies.

Kedgeree is made with rice and fish.

Fish sauce is a common ingredient in the Far East. Terms to look out for are Nuoc Mam and Nam Pla.

Fish sauce can be made with shellfish as well as fish.

Patum Peperium (Gentleman's Relish) is a spread made with anchovies.

Check the ingredient lists on ready-made Oriental sauces, pastes and prepared meals. In fact check the ingredient lists of all food for unexpected ingredients.

The above list is not exhaustive. If you are not sure of any product, question catering staff or shop staff.

Iodine
People with shellfish allergy are sometimes warned against iodine, an element present in a wide range of items including shellfish, seaweed, cleaning products, and X-ray dyes. However, iodine allergy is unrelated to shellfish allergy. The allergen present in shellfish is not iodine but muscle protein in the flesh.

Shellfish shell and skeleton derivatives
Although it is the flesh of shellfish that contains the allergen, people with shellfish allergy are advised to avoid shellfish shells and skeletons. Glucosamine, used in the treatment of arthritis, is derived from the skeletons of shellfish and is unsuitable for people with shellfish allergy. Chondroitin is a shellfish-free alternative. Chitin, derived from shellfish shells, is used in commercial "fat absorbers" such as Chitosan HD, and should be avoided. Moisturisers can also contain shellfish-derived chitin. Some calcium supplements may contain ground oyster shells.

The cod worm
Some people who think they are reacting to seafood are actually having an allergic reaction to a worm-like parasite called Anisakis (also known as the cod worm). This parasite, relatively common in Spain, can cause urticaria, gastrointestinal upset or even anaphylaxis when present in fresh cephalopods, or hake, anchovy or cod. If you react to a particular fish on one occasion, but subsequently eat it with no problem, you should consider the possibility that the cod worm was responsible. Speak to your doctor.

Latex allergy
On rare occasions, people who think they react to seafood (or other food for that matter) may be reacting to the latex gloves used in preparation. They should consider the possibility that they may be latex allergic and speak to their doctor.

Non-allergic reactions
Adverse reactions to seafood are not always symptomatic of genuine allergy.

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