Histological spectrum of cutaneous reactions to aspirin in chronic idiopathic urticaria

Abstract

Background: 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.

Objective: Histological analysis of 16 biopsies of skin eruptions induced by oral aspirin challenge in patients with CIU.

Design: Microscopic analysis of tissue sections.

Patients: 16 patients with CIU.

Results: 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.

Conclusions: 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.