A child with localized vulval pemphigoid and IgG autoantibodies targeting the C-terminus of collagen XVII/BP180

Localized vulval pemphigoid of childhood (LVPC) has previously been reporte d in six girls. Clinical features and immunopathological data have suggeste d it to be a morphological variant of bullous pemphigoid. Epitope targets o f the autoantibodies of these patients have not been defined in detail, We describe a 9-year-old girl with possible cicatricial LVPC and circulating I gG antibodies directed against native collagen XVII/BP180, its 120-BDa solu ble ectodomain and against the C-terminus of collagen XVII/BP180. No reacti vity was detected towards the NC16A domain of collagen XVII/ BP180. Linear IgG and C3 deposits were found along the cutaneous basement membrane zone. On 1 mol/L salt-split skin, IgG autoantibodies were shown to bind to the ep idermis, and the HLA type II allele DQB1*0301, a marker with significantly increased occurrence in patients with ocular and oral cicatricial pemphigoi d, was identified in this patient. Our data suggest that LVPC is a variant of bullous pemphigoid in which direct immunofluorescence microscopy combine d with immunoblot analysis can deliver valuable diagnostic information for differential diagnosis. However, differentiation between the scarring and n on-scarring course of the disease cannot be made with the present diagnosti c markers and therefore careful follow-up of patients with LVPC is required .