Urticaria: The final common pathway

ABSTRACTUrticaria occurs commonly in children and young adults. In general, a younger and atopic population is usually involved and the lesions are acute, usually less than 6 weeks in duration and it is relatively easy to show a cause and effect, usually by history. The cause of chronic urticaria, which is defined as urticaria lasting longer than 6 weeks, is much more difficult to identify and 80–95% of patients are classified as idiopathic. Many of the patients react with a wheal and flare to their own serum or plasma indicating that they have a histamine-releasing agent in their own serum. Most of these subjects will have urticaria which clears with time but a small minority continue to have urticaria for the rest of their lives.Treatment for patients having known causes is to avoid the triggers and all patients with chronic urticaria need to be treated with H1 antihistamines. Sometimes an H2 antihistamine is added or a tricyclic 'tranquilizer' which has anti H1 and H2 blocking action needs to be used. Those patients who do not respond may need treatment with prednisone which should be reduced to the smallest dosage and discontinued as soon as possible. Patients with hereditary angioedema respond to danazol, stanozol or epislan-aminocaproic acid or tranexamic acid