A controlled trial of therapy in chronic urticaria.

Nineteen patients with chronic idiopathic urticaria (duration 2 to 192 mo) referred to our clinic as therapeutic failures were treated sequentially with five regimens. These were administered orally in a double-blind random sequence and included hydroxyzine pamoate (25 mg q.i.d.) plus one of the following: (1) placebo, (2) terbutaline (2.5 mg q.i.d.), (3) cyproheptadine (4 mg q.i.d.), (4) chlorpheniramine (4 mig q.i.d.), (5) cimetidine (300 mg q.i.d.). Therapeutic response was assessed by patient's subjective choice, symptom diary scores, and suppression of wheal response to intradermal injections of histamine and compound 48/80. At least 35% improvement was noted in all patients with an average optimal response of 70%. The hydroxyzine-cimetidine combination was favored by 11 of 19 (58%) patients, in addition to producing the lowest symptom scores and the greatest histamine-48/80 wheal suppression. These results support the efficacy of combination H1 and H2 antihistamines in the management of some patients with difficult chronic urticaria.