Pemphigoid vegetans represents a bullous pemphigoid variant : patient's IgG autoantibodies identify the major bullous pemphigoid antigen

Pemphigoid vegetans is a rare disease; only four cases have been reported. The relationship of pemphigoid vegetans to bullous pemphigoid is not completely defined. We describe a case in a 77-year-old woman who had multiple well-circumscribed, erythematous, erosive, and vegetating plaques in the axillae and inframammary areas and in the neck. Microscopic examination revealed epidermal hyperplasia, dermoepidermal junctional separation, and prominent dermal eosinophilia. In the perilesional skin IgG was deposited linearly at the basement membrane zone. In addition, our patient's IgG autoantibodies, primarily the IgG4 subclass, reacted with the epidermal side of salt-split normal human skin and with the 230 kd major bullous pemphigoid antigen. We conclude that pemphigoid vegetans is best classified as a bullous pemphigoid variant.