Unilateral bullous pemphigoid without erythema and eosinophil infiltration in a hemiplegic patient

In this report, we describe an 88-year-old male stroke patient with unilateral bullous pemphigoid limited to the hemiplegic side. Physical examinations revealed multiple tense bullae with clear and/or bloody contents without apparent erythema on the right thigh and lower leg, accompanied by erosions on the right chest. Histopathologically, no eosinophils were infiltrated into and around the subepidermal bullae. Immunofluorescence revealed deposited and circulating immunoglobulin (Ig)G anti-basement membrane zone antibodies. Immunoblot assays using various antigen sources and enzyme-linked immunosorbent assay revealed that IgG antibodies in this case reacted with unique epitopes between NC16a and C-terminal domains on the 120-kDa LAD-1, the extracellular truncated form of BP180. Three observations were unique in our case. First, the distribution of bullae in our patient was limited to the hemiplegic side. Second, there was no apparent erythema clinically and no eosinophilic infiltration histopathologically. Third, the patient achieved remission without the use of oral corticosteroids. The unusual epitopes in this case may contribute to these phenomena.