HAY FEVER

also called rose fever or allergic rhinitis seasonally recurrent bouts of sneezing, nasal congestion, and tearing and itching of the eyes caused by allergy to the pollen of certain plants, chiefly those depending upon the wind for cross-fertilization, such as ragweed in North America and timothy grass in Great Britain. In allergic persons contact with pollen releases histamine from the tissues, which irritates the small blood vessels and mucus-secreting glands; symptoms may be aggravated by emotional factors. Antihistamine drugs may provide temporary relief, but the most effective long-range treatment is desensitization by injections of an extract of the causative pollen. Hay fever, like other allergic diseases, shows a familial tendency and may be associated with other allergic disorders, such as dermatitis or asthma; unless properly treated, about one-third of patients with hay fever develop asthma.