Linear lupus erythematosus profundus in an adolescent

A 17-year-old Italian boy presented a 3-year history of violaceous, macular lesions of the breast and internal surface of the right arm with a characteristic linear distribution. A biopsy specimen revealed a lymphohistiocytic panniculitis, and periappendageal and perivascular infiltrates of lymphocytes occasionally involving the blood vessel walls in the deep dermis and hypodermis. Focal hydropic degeneration of basal cells was also evident. Direct immunofluorescence revealed linear focal deposits of IgM at the dermoepidermal junction. Antinuclear antibodies were positive. Histopathology, direct immunofluorescence and immunological assays allowed us to diagnose lupus erythematosus profundus. To our knowledge, only one other case of linear lupus erythematosus profundus has been reported in the literature until now.