How can an allergy be diagnosed?

There are several ways in which a formal food allergy diagnosis can be made – all should be made through an allergy specialist doctor, preferably, for children, a paediatric allergy specialist. There are several NHS centres across the UK that now have paediatric allergy doctors and nurses and there has also been a rise in the amount of general paediatricians who have a specialist interest in food allergy.

Once you’re seen by an allergy specialist they’re likely to test your child with a skin prick test. Using a small amount of liquid onto the forearm, a small prick is used to introduce the allergen into the top layer of skin. If your child is allergic to the allergen, a small hive will appear within 15-20 minutes. If not, no hive will appear.

By using this test you will be able to leave the appointment with an understanding of your child’s allergies, as the results will be discussed with you before you leave. Skin prick testing is very safe, but must always be carried out by the trained doctors or nurses within the allergy department.

There’s also a blood test that your doctor may request, this is commonly called a RAST test – this result will take longer (anywhere between a week to three weeks). Both of these tests are used as a guide, and must be discussed with medical staff.

What’s the difference between an allergy and intolerance?

Food allergies and food intolerances are both a type of food sensitivity. When someone has a food allergy, their immune system reacts to a particular food as if it isn’t safe. If a food allergy is severe, the exposure to that food can cause a life-threatening reaction. This means that people with food allergies, and in particular a peanut allergy, need to be extremely careful about what they eat.

Food intolerance doesn’t involve the immune system and is generally not life-threatening. But if someone eats a food they are intolerant to, this could make them feel ill or affect their long-term health.

Food allergies in children

Food allergies in children are becoming more common in the UK, with between 2.2% – 5.5% of children suffering their first allergic reaction in the first year of life (Du Toit, 2009).

The most common food allergies in children are cow’s milk, hen eggs, wheat, soya, peanut, tree nuts, sesame and kiwi. The majority of children outgrow their cow’s milk or egg allergy between the age of 5 or 6, however peanut and tree nut allergies are seen as troublesome, as these are seldom outgrown.

What is an allergic reaction?

An allergic reaction can occur after a child has eaten something; it can be within 10-15 minutes, or up to 2 hours after the food has been consumed. The reaction can be mild with a few hives (white itchy lumps), urticarial rash (red, inflamed rash) or swelling of the lips, eyes or face. The reaction may become more severe and involve lethargy, drowsiness or difficulty in breathing. If any of these symptoms occur you should always seek further medical advice either through your GP or local A & E department.

Will my child outgrow their allergy?

The majority of children will outgrow a cow’s milk or egg allergy by the time they are 5 or 6. However, this is not always the case. Most allergy centres will see you annually to re-test your son or daughter to see if there has been any change in their allergic status. Although there have been cases of children outgrowing peanut and tree nut allergies, these are rare. It’s also very important to only ever re-introduce a food under the strict guidance of your paediatric allergy doctor or nurse, and with the help of a specially trained dietitian.

I think my child may have a food allergy – what should I do?

If you suspect your child has a food allergy, it’s important to seek further medical advice. Firstly seek your GP’s advice, you may then be referred to an allergy centre within the NHS. If your child has had an allergic reaction and is unwell please seek immediate medical attention through either your GP or local A&E department.
Always seek further medical advice if unsure.

Where can I find more information and advice about food allergies?

The following organisations’ websites contain a wealth of relevant information and resources that can be downloaded:

The Anaphylaxis Campaign

AllergyUK

The British Society for Allergy and Clinical Immunology (BSACI)

Coeliac UK