Histamines are the chemicals your body produces when it reacts to something you're allergic to. They are part of your body's defence system and can cause you to sneeze, cry or make your skin itchy as it tries to get rid of the allergen in your system.  

(Anti)histamines are used to stop the histamines which make you itch and cause swelling when you're allergic to something.This type of treatment has been used for years to treat conditions like hay fever, nasal allergies and skin conditions such as urticaria and eczema.

Older types of antihistamines have been fazed out because they were known to cause drowsiness. The new types are safe and don't cause drowsiness, so we tend to recommend these.

You can buy many antihistamines over the counter at any chemist, but there are some you can only get with a prescription.

Find out more about our asthma and allergy services

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: 020 7351 8892
Fax: 020 7351 8949