Three case reports of post immunization and post viral Bullous Pemphigoid: looking for the right trigger

BACKGROUND Bullous pemphigoid (BP) is a blistering skin disorder infrequent in infancy and rarely reported in medical literature. CASE PRESENTATION Here we describe three cases of BP which were referred to our department in the last 15 years. Two of them developed an eruption of bullous lesions just a few days after vaccination for diphtheria, tetanus, pertussis, poliomyelitis, hepatitis B and Haemophilus influenzae B. The third patient developed the same blistering lesions shortly after herpetic stomatitis. In all three cases, clinical diagnosis was confirmed by histological examination which showed subepidermal bullae with a dermal inflammatory infiltrate, and direct immunofluorescence of perilesional skin showed linear IgG and C3 deposits along the basement membrane zone. Immunoblot assay was positive for BP antigen 180. Treatment with oral prednisone was instituted and the lesions resolved in two out of three patients; the third one was treated with an immunosuppressive agent (tacrolimus) and corticosteroid and subsequently with intravenous immunoglobulin and plasmapheresis, due to an underlying complex autoimmune disease. CONCLUSION Although the mechanism of induction of BP is still unclear, the close relationship between trigger events (immunization or viral infection) and onset of the disease arises a possible association.