Anaphylaxis is a serious allergic reaction that can be life-threatening or fatal. The reaction happens quickly and usually involves difficulty in breathing, feeling faint or lightheaded and can lead to a collapse. People might get skin wheals and/or angioedema before they start having difficulties in breathing. 

Key triggers include food, drugs and stinging insects such as bees, wasps and hornets. Sometimes it is difficult or impossible to find a clear trigger; sometimes it is caused by a combination of occurrences. For example, people may only have anaphylaxis when exercising and sometimes a combination of exercise and certain foods or medications can cause the problem. 

Anyone who has had an anaphylactic reaction should have specialist follow-up in order to identify and avoid the trigger(s). Sometimes their history and skin or blood tests can be enough to identify the trigger, but diagnosis may also involve careful challenge (provocation) testing in hospital, under medical supervision. Patients who have had an anaphylactic reaction should receive written information listing the triggers involved and giving a plan of how to manage any future episodes. Self-injected adrenaline is the best treatment to give immediately. Other drugs such as corticosteroids and antihistamines may be given in addition. In the case of anaphylactic reactions to insect stings, specific allergen immunotherapy (‘desensitisation’) may be necessary to protect against further allergic reactions. 

The Anaphylaxis Campaign website offers further support for those living with anaphylaxis and their families.

Skin prick testing

Skin prick testing is a universal allergy test and often used to find out what is causing an allergy. 

Oral food challenge

Oral food challenges are tests that use suspected food allergens. The foods that we most commonly test are peanuts, tree nuts and shellfish.

Drug challenge testing

This form of testing comprises of a series of tests to see if you are allergic to certain drugs, all under close medical supervision. 

Molecular diagnosis

Molecular diagnosis covers tests which can assess whether someone has antibodies against a particular protein in a food which causes an allergic reaction.

Nose clinic tests

Patients coming to the nose clinic will have a number of tests, often including an examination using an endoscope, skin prick testing, chest peak expiratory flow and spirometry.

Nasal sprays

Corticosteroid nasal sprays or drops are the most effective standard treatment for hay fever and other nasal allergies. 


Antihistamines prevent histamine causing the itching and swelling that occurs when you have allergies.

Allergen immunotherapy

Allergen immunotherapy is a treatment in which the allergen that triggers an allergic reaction is given in order to suppress unnecessary reactions.

Allergy team contact information


Fulham wing/South block, Fulham Road

Tel: 020 7351 8892
Fax: 020 73518949