The selective cyclooxygenase-2 inhibitor rofecoxib may improve the treatment of chronic idiopathic urticaria.

Abstract

Sir, Chronic idiopathic urticaria (CIU) is one of the most common skin diseases, affecting about 3% of the Western population. Although the symptoms of CIU are primarily due to mast cell degranulation and subsequent histamine release, treatment with H1 antihistamines is often insufficient. One explanation for this is that the actions of other mast cell mediator types have been overlooked, such as prostaglandins and thromboxanes, which display inflammatory properties similar to those of histamine. Prostaglandins and thromboxanes are formed from arachidonic acid by the actions of the enzymes cyclooxygenases (COXs), of which there are two isoforms, with the inducible COX‐2 being responsible for pseudoallergic and other inflammatory responses. Reasoning that COX‐2 might therefore be a relevant target in the treatment of urticaria we investigated the clinical efficacy of a combination therapy comprising the H1 antihistamine desloratadine and the selective COX‐2 inhibitor rofecoxib. Ten caucasian patients with CIU, in whom conventional therapy with H1 antihistamines did not resolve the symptoms, chose to undergo this experimental treatment. The diagnosis was based on the patients' history and extensive laboratory investigations to exclude underlying causes. Disease severity was assessed using a scoring system based on weal formation and pruritus according to a recent consensus publication.1 A patient was considered ‘clinically improved’ if their score (on a 0–6 scale) declined by a value of at least 2. The patients were initially treated with the H1 antihistamine desloratadine 2 × 5 mg daily for 4 weeks, followed by a combination treatment with desloratadine 2 × 5 mg and rofecoxib 25 mg daily for another 4 weeks.