Intertriginous bullous morphea: A clue for the pathogenesis?

Bullae occurring in lesions of morphea are uncommon. The cause of bullae formation in morphea is multifactorial, although lymphatic obstruction from the sclerodermatous process is considered the likeliest cause. Bullous morphea may be confused clinically with lichen sclerosus et atrophicus since both diseases may cause bullae in sclerodermatous plaques. A 69-year-old woman presented with a history of generalized morphea diagnosed 9 years earlier; and a 1-month history of pruritic bullae on her inframammary folds, axillary regions, lower abdomen, upper extremities and inguinal folds. Physical examination revealed multiple erythematous erosions, hemorrhagic vesicles and eroded bullae with slight scale or crusts overlying hypopigmented, indurated, shiny plaques. Skin biopsy revealed prominent edema in the papillary dermis, resulting in bulla formation and thickening of collagen fibers within the dermis. Direct immunofluorescence was negative. According to histologic and clinical features, the diagnosis of bullous morphea was established.