Pr e sen tat ion of C a seDr. Sarah Gee (Dermatology): An 82-year-old man was admitted to this hospital because of persistent skin lesions on the hands.The patient had a history of diabetes mellitus and recurrent hidradenitis suppurativa. Five weeks before admission, he was admitted to another hospital because of drainage from a perineal abscess that was unresponsive to cephalexin. On examination, he reportedly had a small abrasion on his left hand, which he thought was caused by a dog bite. The administration of cephalexin was discontinued, and piperacillin-tazobactam and vancomycin were begun. During the following week, increasing erythema and an enlarging hemorrhagic bulla developed on the dorsum of the left hand and a diffuse, urticarial, and purpuric rash developed on the torso. Laboratory testing reportedly revealed thrombocytopenia. Débridement of the lesion of the left hand was performed; pathological examination of a specimen reportedly showed acute inflammation and granulation tissue. After débridement, the lesion worsened and similar lesions developed on the right hand, on the metacarpophalangeal joints. The lesions were reportedly painful to the touch and to manipulation, with ulceration extending to the tendons. Glucocorticoids were administered. On the 10th hospital day, a biopsy specimen of the skin of the right abdomen was obtained; pathological examination reportedly showed leukocytoclastic vasculitis and no microorganisms. The administration of piperacillin-tazobactam and vancomycin was stopped, as was subcutaneous heparin (begun during admission), and ciprofloxacin and linezolid were begun, in conjunction with a topical antimicrobial solution for the hands. The lesions expanded to include the proximal interphalangeal joints and became more erosive and painful. On the 13th day, the patient was transferred to a second hospital for evaluation and management of the skin lesions.At the second hospital, the patient reported weight loss of approximately 2.3 kg per week during the previous month and intermittent diarrhea. On examination, the temperature was normal. On the dorsal surfaces of the hands were well-demarcated, edematous, friable, erythematous-to-violaceous plaques, with gray discoloration at the margins (Fig. 1A). Smaller violaceous, erythematous, edematous plaques were present on the trunk and thighs. A biopsy specimen of the skin on the dorsum of the right hand was obtained; pathological examination revealed a superficial and deep,
