Unique immunobullous disease in a child with a predominantly IgA response to three desmosomal proteins

We report the case of a 15-year-old girl who presented at; 11 years of age with an interesting, acquired and, to our knowledge, unique blistering dise ase. It involved both skin and mucous membranes with extensive oral and per iungual lesions, clinically resembling paraneoplastic pemphigus. Skin biops y showed an inflammatory cell infiltrate in the upper dermis with numerous leucocytoclastic nuclear fragments, neutrophilic papillary microabscesses a nd a small subepidermal bulla. Direct and indirect immunofluorescence studi es showed marked intercellular staining with IgA and less prominent stainin g with IgG. Granular deposition of IgA and, to a lesser extent IgG and C3, was also seen along the basement membrane zone. Immunoblotting and enzyme-l inked immunosorbent assay studies showed both IgG and IgA antibodies to des mocollin, desmoglein 3 and desmoplakin. However, despite extensive investig ation, no underlying neoplasm was found. Treatment with dapsone and sulphap yridine proved ineffective but: methylprednisolone and azathioprine have re duced the blistering. We believe that this patient: is unique for her combi nation of IgA and IgG antibodies to desmoplakin, desmocollin and desmoglein 3, although further studies may provide further clarification.