The causative agent is usually recognized by the patient. Chronic Urticaria This is urticaria occurring almost daily and lasting more than two months. In the majority of patients, no cause or significant aggravating factors can be found. Physical urticaria may be present as well in some patients. Food allergy is seldom a cause of chronic persistent urticaria even though some foods may aggravate it.
Emotional stress is known to aggravate chronic urticaria in some.
Fifty per cent of cases of chronic urticaria, clear spontaneously in about 6 months. The best treatment for urticaria is to identify and avoid the cause and any aggravating factors. While investigating the cause, anti-histamines are prescribed for symptomatic relief. Antihistamines, when taken orally, take about 90 minutes to relieve an already formed hive. They work best if taken on a regular basic to prevent the formation of hives.