The Australasian Society of Clinical Immunology and Allergy

Allergic reactions to cow's milk, soy, wheat and egg usually resolve by the time a child starts school. Unfortunately, reactions to seafood and nuts usually persist. A condition known as oral allergy syndrome is most commonly observed for the first time in young adults.

Soy allergy is common in infants

Soy allergy is a common allergy of infancy, often first experienced when a baby is given soy milk formula because of known cow's milk allergy. Around 1 in 5 children allergic to cow's milk have problems with soy as well. Like cow's milk, it is hard to avoid because it finds its way into so many processed foods, including:

• baked goods such as bread, batters, cereals, sausages
• as a binder in small goods
• in salads and canned beans

Soy lecithin is an emulsifier (322) found in many foods such as chocolate, margarine, and carob. Occasionally, people who are very sensitive to soy will have reactions to this as well. Other names for soy include soya, soy flour, soya protein, vegetable gum, textured vegetable protein, hydrolysed vegetable protein, lecithin, bean curd, soya bean paste (Miso, Tempe), and tofu.

Egg Allergy is very common in infants

Egg allergy is most common in infants less than 1 year of age. Up to 1 in 20 children may have a transient allergy to egg. Fortunately, around 80 % of egg allergy resolves by the time the child starts school. Use of terms such as egg yolk and egg white, albumen, egg powder or solids on the label may also indicate the presence of egg in a food.

Most people allergic to hen's egg are also allergic to similar proteins in other bird eggs like duck, so these are best avoided as well. Cooked egg is sometimes better tolerated than raw egg, so some children with mild egg allergy seem to be able to tolerate small amounts in cakes or slices. Common foods containing egg include:

• malted drinks
• custards, mousse
• souffles, meringues
• glazed rolls or pastries
• cakes, slices and macaroons
• some soups and sauces (such as Hollandaise)
• rissoles or meat loaf (used as a binding agent)
• desserts (such as waffles, pavlova mix, confectionery)

Allergy to wheat and cereals usually resolves in the first few years

Allergic reactions to wheat and other cereals are most common in infants and usually resolve within the first few years of life. Whilst some children develop hives (urticaria), other common symptoms are those of worsening eczema. This usually occurs within a few hours of eating wheat or other cereals that an individual is sensitive to.

Occasionally delayed reactions occur after the food is eaten regularly over several days, resulting in eczema or sometimes diarrhoea, or poor weight gain. In this situation, skin prick allergy testing is often negative and the diagnosis rests on temporary elimination from the diet followed by deliberate food challenges under medical supervision.

Wheat and cereal allergy is occasionally seen for the first time in adults. Many suffer from allergic rhinitis to grass pollen (hay fever) as well.

It is important to distinguish allergic reactions to wheat from coeliac disease or food intolerance associated with eating wheat products. Information on food intolerance is available on the ASCIA website www.allergy.org.au/content/view/155/142/ 

Allergy to one meat usually means allergy to all meats

Meat is a major source of protein in Western diets, and allergic reactions to beef and chicken are the most common. Unfortunately, recent studies suggest that individuals allergic to one meat may have sensitivities to similar allergens present in multiple mammalian meats.

Reactions to other foods are less common

Allergic reactions to soy, wheat and eggs (as well as cow's milk, peanuts, tree nuts and seafood - described in other articles available on the ASCIA website  www.allergy.org.au/content/view/290/235/) are the most common type of food allergens.

However, reactions to a diverse range of food and plant derived products such as spices, vegetable gums, gelatine, herbal remedies (such as Royal Jelly, Echinacea), vegetables and meats have all been described.

Oral Allergy Syndrome

About 1 in 10 people with allergies to some grass or tree pollens will complain that some uncooked vegetables or fresh fruits and nuts will make their mouth and throat itchy or swell. This is known as Oral Allergy Syndrome. In this condition, people are allergic to proteins that are present in pollens as well as these foods. If the food is heated, the protein is often destroyed. This is why they can usually eat the cooked food without a problem. More serious allergic reactions sometimes occur, particularly if exercise is undertaken soon after eating a lot of this type of food. A small number of unfortunate people are allergic to many fruit and vegetables.

Allergic reactions to inhaled foods are uncommon

Allergic reactions to food in the form of fine dust are uncommon, and mainly occur in food handlers. Examples include asthma induced by the fine dust of coffee or soy beans in processing plants, seafood allergens in some factories or wheat dust in bakeries. Sometimes people with severe food allergies find that even the smell of foods can trigger symptoms. Fortunately, this is a relatively rare complaint and symptoms are usually not severe.

© ASCIA 2010  

The Australasian Society of Clinical Immunology and Allergy (ASCIA) is the peak professional body of Clinical Immunologists and Allergists in Australia and New Zealand. 

Website: www.allergy.org.au

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Postal address: PO Box 450 Balgowlah NSW Australia 2093
  

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Content last updated January 2010