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WHAT ARE FOOD ALLERGIES?

 

Food allergies and food intolerance are controversial issues. One fifth of people believe that they have a bad reaction to certain foods, while surveys show that only about two in every 100 have an adverse reaction that is measurable.

 

Young children are more likely than adults to be affected, however, and some allergies, such as peanut allergy, are on the increase. The good news is that most children grow out of their food allergy by the age of five.

 

Symptoms

 

If your child has a food allergy, her immune system sees a certain food as a foreign invader (allergen), and, as with an infection, produces antibodies. The next time your child eats the food, a war breaks out between the allergen and the antibodies. The symptoms this causes include:

 

• Diarrhoea
• Facial swelling
• Vomiting           
• Sinus headaches
• Abdominal pain        
• Glue ear
• Wheezing         
• Bloodshot eyes
• Runny nose, sneezing          
• Your child may also seem irritable and have difficulty sleeping, due to the effects of the allergic reaction
• Rash
• Burn-like rash around the anus       

 FOOD ALLERGY OR FOOD INTOLERANCE?

 

Food allergy can produce the same symptoms as food intolerance. An allergy involves the immune system, intolerance is linked to an inability to digest food.

 

Food allergy: these are of special concern to parents because in their most severe form they can cause life threatening reactions. A food allergy triggers an abnormal reaction in the immune system.

 

Food intolerance: this is an adverse reaction that doesn't involve the immune system; it may be related to an enzyme deficiency. If a child is lacking in the enzyme lactose, it may lead to an intolerance of milk.

 

WHO IS SUSCEPTIBLE?

 

Some children may be more sensitive to general allergic reactions than others and this condition is known as atopy. It means your child is more likely to suffer from eczema, asthma and hay fever.

 

Atopy runs in families - if both parents suffer from allergies, a child has a 60 per cent chance of developing them, too.

Some argue that the increase in peanut allergy reflects the general increase in atopy over 20 years. Others think that it is due to mothers eating peanut butter when breast-feeding, and recommend that foods known to cause allergies should not be given in allergy-prone families until the immune system has a chance to mature, usually between the ages of  two and three.

 

Difficulties with diagnosis

 

In a wide-ranging diet; it is not always easy to pinpoint the cause of an allergy- some children are sensitive to more than one food or to other allergens as well, for example, pollen or cat fur.

 

• If you suspect a particular food, keep a diary of what your child has eaten, where he's been and what he's been doing, then talk to your doctor. You may be referred to an allergy clinic where specialist’s will take a detailed history and carry out tests to diagnose the problem food. 
• There are two main types of test. In the skin prick test a small amount of an allergen is placed in a solution on the forearm or back and then the skin is pricked with a lancet through the drop. A weal and raised red area after 15 minutes generally show an allergic reaction. 
• The RAST' test is a blood test that checks for the presence of specific antibodies produced to defend against typical allergens. 
• Neither of the tests are always accurate, particularly with young children, as it takes time for their antibody response to build up. Sometimes a skin prick test may produce a false negative result if antihistamines have been taken previously.The skin type and the quality of testing can all affect accuracy, too. 
• Occasionally, if these tests fail to identify the allergy, an elimination diet may be suggested, which means cutting out the foods that commonly cause allergic reactions and then re-introducihg them gradually. 
• A food challenge test introduces your child to a likely allergen, in the presence of a. doctor, to diagnose the problem of food intolerance. 

Peanut allergy

An estimated one in 200 UK children are allergic to peanuts, which can trigger a potentially fatal reaction, anaphylaxis. Symptoms include abdominal pain, facial swelling, breathing problems and asthma. It requires immediate treatment with an adrenaline injection.

 

Prevention better than cure

Once a problem food is diagnosed, the basic treatment is excluding it from your child's diet. This should always be done with the help of a dietitian to ensure that the child's diet remains balanced.

 

There are substitutes for most allergenic foods, for example, with a cow's milk allergy a soya milk substitute is suggested. But foods appear under unexpected names - milk may be listed as casein, whey, lactalbumin and lactose; eggs as albumen and egg lecithin; wheat flour as durum semolina and farina; peanuts as groundnuts.

 

A family with a history of allergies should cut out trigger foods during pregnancy and breast-feeding, delay weaning until six months and avoid eggs and nuts for two years.

 

Common Food Allergens

Four of the most common food allergens are:

*  Dairy products

*  Wheat

*  Egg whites

*  Peanuts

 

These are responsible for nearly 90 per cent of allergies. Other allergenic foods are tree nuts (walnuts, almonds, brazils, 'hazelnuts, cashews), sesame seeds, citrus fruits, soya, fish and sheIlfish. Some children react to additives, e.g. tartrazine (E 1 02), antioxidants and preservatives.

 

For  More  Information:  Please  consult  your  physician  on  your  next  visit.