Childhood bullous pemphigoid: a clinicopathologic study and review of the literature.

Bullous pemphigoid (BP) is an acquired bullous disorder that predominantly affects the elderly. It is rare in children but when it occurs, there is considerable clinical and histologic overlap with other acquired or congenital blistering disorders. A definitive diagnosis of childhood BP requires direct immunofluorescence and, in some cases, characterization of the target antigen. Three cases of childhood BP are presented, with their histologic and immunofluorescence findings. The first was a 5-month-old male infant who presented with erythema and bullae of the palms and soles and was found to have linear deposition of IgG and C3 along the dermoepidermal junction on direct immunofluorescence (DIF). Histopathologic examination revealed a subepidermal blister containing eosinophils. Type IV collagen was demonstrated along the floor of the blister cavity by a direct immunoperoxidase technique. The second case was an 8-month-old female infant who presented with a blistering eruption of her palms and soles that then became widespread. Direct immunofluorescence showed linear IgG and C3 at the dermoepidermal junction, with laminin deposition at the base of the blister. The third case was a 7-year-old female with bullae and erosions on the vulva and vaginal mucosa. A subepidermal blister was seen on microscopic examination whereas immunofluorescence demonstrated linear IgG and C3 deposition at the basement membrane zone (BMZ). A literature review uncovered 50 cases of childhood BP confirmed by direct or indirect immunofluorescence, or both, and often with evidence of autoantibodies against either the 180 kD or the 230 kD human bullous pemphigoid antigens (BP180 or BP230). This review was used to delineate characteristics of childhood BP, including the newly proposed subtypes: infantile BP and childhood localized vulval BP. Infantile BP presents within the first year of life and is characterized by BP-like lesions on erythematous or normal acral skin. Localized vulval BP is a self-limited, nonscarring BP-like process that involves only the vulva. Both subtypes are normally self-limited and respond well to either topical or systemic steroids, if treatment is initiated before the disease becomes widespread.