Granuloma multiforme.

CASE 1: A 51-year-old woman presented with skin-colored annular lesions on the upper chest, neck, and dorsa of the hands of 1-year duration. The lesions initially started as small papular lesions, which gradually evolved to form large annular and polycyclic lesions. Initially, the lesions were associated with a burning sensation and pruritus. She had no other systemic complaints. Examination revealed 5-6 annular, polycyclic lesions distributed over the upper chest, neck, and dorsa of both hands, varying in size from 1 to 5 cm. All the lesions had a prominent erythematous to skin-colored, irregular, papular border which was firm in consistency (Figs 1 and 2). Central clearing and minimal atrophy were evident in larger lesions. There was no sensory loss or peripheral nerve thickening. Clinical possibilities entertained were granuloma annulare, granuloma multiforme, and annular sarcoid. Routine investigations, including hemogram, renal and liver functions, blood sugar levels, chest X-ray, and urine examination, were within normal limits. A skin biopsy taken from the edge of a lesion revealed foci of collagen degeneration surrounded by an inflammatory infiltrate composed of many histiocytes and multinucleated giant cells. In addition, there were perivascular and periadnexal lymphocytic aggregates. No acid-fast bacilli (AFB) were detected. These findings were consistent with a diagnosis of granuloma multiforme (Fig. 3). CASE 2: A 47-year-old man presented with annular skin-colored lesions associated with a mild burning sensation of 8 months' duration. On examination, 2-3 annular, arciform lesions were distributed over the upper chest and neck. The lesions ranged in size from 2 to 7 cm in diameter, were irregular in shape, and were rimmed by a well-defined raised papular border. Again, there was no sensory loss or peripheral nerve thickening. Histopathology of the skin from the edge of the lesion showed multiple areas of histiocytic granulomas with focal necrobiosis and prominent multinucleated giant cells, findings consistent with granuloma multiforme.