Also known as allergic rhinitis, this is caused by an ALLERGY to the pollen of grasses, trees and other plants. Contact with the particular pollen to which the sufferer is allergic causes HISTAMINE release, resulting in a blocked, runny nose and itchy, watering eyes. It affects approximately 3 million people each year in the UK.

The mainstays of treatment are ANTIHISTAMINES, taken by mouth, and the use of steroid and cromoglycate nasal sprays and eye drops. Occasionally desensitisation by injection may be offered if the particular allergen is known.