Fixed drug eruption of the oral mucous membrane.

Twenty-five patients with lesions of fixed drug eruption on the oral mucous membrane with or without cutaneous lesions were studied. Seventeen patients showed both cutaneous and oral mucous membrane involvement, while eight patients showed involvement of only the oral mucous membrane. Eighteen cases had bullous and erosive type of lesions while seven had lesions which were edematous and hyperpigmented with an erythematous halo. Diagnosis was confirmed in each case by provocation test. Cotrimoxazole, oxyphenbutazone and tetracycline were the most common causative drugs.