Linear dermo-epidermal IgA deposition in bullous pemphigoid.

A case is reported of a patient with a bullous eruption with in vivo linear deposition of IgA and complement (C3) along the basement membrane zone of perilesional skin (DIF method). Some data presented here are in favour of the concept that cases of linear in vivo deposition of IgA alone, or in combination with other IF findings, might be classified as bullous pemphigoid (BP). Clearing of the lesions due to oral prednisone therapy was accompanied by disappearance of complement deposition, while IgA deposition remained unchanged. Some aspects of tissue injury in this case are briefly discussed.