33379 Melanophages save the day: A case of generalized bullous fixed drug eruption

Abstract

A 29-year-old female was seen via inpatient dermatology consultation for acute erosive stomatitis. Upon admission for sickle cell crisis, the patient had an incidental urinary tract infection and was treated with trimethoprim-sulfamethoxazole for 3 days. On physical examination, she had painful superficial erosions of the upper and lower mucosal lips extending onto the vermillion as well as the distal and ventral tongue. Five large dusky violaceous plaques with overlying superficial erosions were seen on the bilateral proximal medial thighs, arms and on the left lateral abdomen. Punch biopsy of the violaceous plaques revealed a vacuolar interface dermatitis with full thickness necrosis overlying an inflammatory infiltrate with occasional interstitial eosinophils and many melanophages at the level of the superficial vascular plexus. While the pathologic differential diagnosis included EM as well as SJS/TEN, the melanophages, eosinophils and clinical findings favored a diagnosis of generalized bullous fixed drug eruption (GBFDE) secondary to trimethoprim-sulfamethoxazole. GBFDE is a particularly severe variant of FDE which often includes mucosal erosions. Differentiation from SJS/TEN may sometimes be clinically and histologically difficult, and patients may suffer high morbidity and mortality. In our patient, we treated aggressively and cautiously with IV methylprednisolone followed by oral prednisone with no disease progression and eventual complete resolution. The clinical findings suggestive of FDE along with dermal melanophages and eosinophils allowed a cautious but confident diagnosis of GBFDE without need for transferring our patient to a burn unit.