Bullous Prurigo Pigmentosa

Prurigo pigmentosa is a type of inflammatory dermatosis characterized by symmetrical pruritic erythematous papules that normally resolve with reticular pigmentation. In severe cases, edematous infi ltrative plaques may be found, but usually no vesicles or bullae. We presented a 32-year-old Taiwanese female, a case of insulin dependent diabetis mellitus with sudden onset of vesicobullae upon erythematous papuloplaques over the face, neck and upper trunk, preceding an episode of diabetic ketoacidosis. Histopathology of the skin lesion revealed an intraepidermal bulla fi lled with neutrophils, atrophic epidermis, exocytosis, perivascular mononuclear cells and neutrophils infi ltration involving dermis and hair follicles. The vesicobullae subsided after control of ketoacidosis by subcutaneous insulin injection. Our fi nal diagnosis was bullous prurigo pigmentosa. Doxycycline was then added to complete the treatment and it was found to be effective in resolving erythema and post-infl ammatory hyperpigmentation. Bullous prurigo pigmentosa is a rarely documented entity, we herein report a case and review the literature. (Dermatol Sinica 27: 103-110, 2009)