H1 antagonists in the management of the itch of urticarias.

This article reviews the effect of H1 antihistamines on the pruritus of urticaria, from articles in which their therapeutic effect on chronic idiopathic and physical urticaria is assessed. In limited studies available pruritus improved concomitantly with wealing by an average of two thirds, though the response in individual patients was variable. In some physical urticarias the pruritus and wealing showed disproportionate improvement compared to erythema. The minimally sedating H1 antihistamines were as effective or more effective than classical H1 antihistamines. The dose of antihistamines that totally abolished a histamine weal only partly reduced urticarial weals (therefore by inference also of the associated pruritus). Additional therapy aimed at pruritogenic mediators other than histamine would be expected to improve urticarial pruritus.