Traditionally, food allergy is diagnosed using a patient's history in combination with either skin prick testing with standard allergen reagents or specific immunoglobulin E (IgE) estimation from a blood serum sample. However, oral food challenge is the gold standard. 

A major advance in the diagnosis of food allergy has been the development of tests which can measure whether individual food proteins are involved in allergic reactions. For example, peanuts have 13 or more allergens (proteins) we know about, and some of them are involved in a primary allergy to peanuts and some in cross-reacting food allergies. Assessing whether someone has antibodies against a particular protein in a food can help a great deal with diagnosis. This is especially important when trying to assess whether someone has a primary allergy to peanuts and needs to avoid even traces of them in foods; or whether their allergic symptoms are caused by antibodies to pollens, such as trees or grass, cross-reacting to peanuts because the proteins are very similar. 

If the allergy is due to a cross-reaction, then the chance of a severe reaction is much lower, and there is no need to avoid foods containing traces of peanuts. This technology is a recent innovation and is not often available, except in specialised allergy clinics. This Trust has been using such technology in food allergy diagnosis for the last five years and the allergy team has considerable expertise in interpreting the results.   

Sometimes severe allergic reactions can occur so it is important to know how to avoid contact with latex if you have this allergy.

Anaphylaxis is a serious allergic reaction that can be life-threatening or fatal.

People with hay fever (rhinitis) have inflamed lining in their nose, which causes it to be blocked, running and itchy, as well as causing sneezing.

Urticaria is a condition which involves the development of itchy wheals (hives) on the skin.

Around 5–10% of people who have a problem with a drug are suffering from a drug allergy, possibly one prescribed by their GP or as part of an investigation in hospital. 

Between 1-10% of adults and children in the UK have a food allergy.

The Trust offers a wide range of allergy services for adults of all ages. This includes specialist services for patients with difficult to manage allergies.

Allergy team contact information

Fulham wing/South block, Fulham Road

Tel:  +44 (0)20 7351 8892
Fax: +44 (0)20 7351 8949