Histological spectrum of cutaneous reactions to aspirin in chronic idiopathic urticaria.

Abstract

During a clinical trial, we obtained 16 biopsies of skin eruptions induced by aspirin in patients with chronic idiopathic urticaria (CIU). In this setting, aspirin triggers skin eruptions through a well-established non-immunological mechanism involving the inhibition of cyclooxygenase type I. This presented the rare opportunity to evaluate histological features of a series of skin eruptions induced by a drug acting through a defined mechanism in a controlled experimental setting. Histological analysis of 16 biopsies of skin eruptions induced by oral aspirin challenge in patients with CIU. Microscopic analysis of tissue sections. 16 patients with CIU. Aspirin (up to 500 mg) induced a restricted range of histological responses with a classic pattern of urticarial tissue reaction occurring in the majority of (12 of 16) cases. Two biopsies showed an interstitial fibrohistiocytic (granuloma annulare-like) reaction pattern. One case showed only a sparse perivascular lymphocytic infiltrate, and paucicellular dermal mucinosis was observed in one case. Polymorphism of histological patterns induced by aspirin suggests that in addition to the drug-specific mechanisms triggering drug eruptions, individual factors also play a role in determining the ultimate histological phenotype of a drug response.