The therapeutic response of urticarial vasculitis to indomethacin.

Ten patients with urticarial vasculitis, characterized clinically by persistent painful urticarial lesions, angioedema, recurrent arthralgia, abdominal pain, and low-grade fever, were selected for study. All patients had histologic evidence of leukocytoclastic vasculitis in the urticarial lesions. Results of direct immunofluorescence microscopy of urticarial lesions were positive in all nine of the patients tested. Treatment with indomethacin in dosages from 25 mg three times daily to 50 mg four times daily resulted in complete clearing of all disease manifestations in six of ten patients within 17 days and partial improvement in three. In eight of the ten patients, disease activity recurred within 48 hours after discontinuation of the use of indomethacin. Gastrointestinal irritation was the only side effect noted. Indomethacin is proposed as an effective mode of therapy in a disorder unresponsive to treatment with conventional medications for urticaria, including high-dose corticosteroids.