Childhood localized vulvar pemphigoid is a true variant of bullous pemphigoid.

BACKGROUND: Childhood localized vulvar pemphigoid has been recently reported in four girls. A fifth child with this proposed rare variant of bullous pemphigoid is described. Moreover, findings in the various immunopathologic studies we performed establish this entity as a true morphologic variant of bullous pemphigoid.

OBSERVATIONS: In situ deposits of IgG in this patient's epidermal basement membrane zone localized to the epidermal side of 1 mol/L of saline-split skin. Moreover, the patient had circulating IgG autoantibodies that bound the epidermal side of 1 mol/L of saline-split skin in indirect immunofluorescence microscopy and immunoprecipitated the 230-kd bullous pemphigoid antigen from biosynthetically radiolabeled human keratinocyte extracts. These laboratory findings are identical to those documented in patients with the generalized "classic" form of bullous pemphigoid.

CONCLUSIONS: This study demonstrates that a child with clinical, histopathologic, and immunopathologic features of localized vulvar pemphigoid had circulating autoantibodies that identify a specific keratinocyte antigen, the bullous pemphigoid antigen, which may serve as a molecular marker for this disease.