Atypical herpes simplex infection masquerading as recalcitrant pemphigus vulgaris

A 57-year-old woman presented with refractory genital erosive disease. One year earlier she experienced gingival fragility; direct immunofluorescence resulted in the diagnosis of cicatricial pemphigoid, and prednisone therapy led to initial improvement. Initial skin biopsy of her genital erosions demonstrated full-thickness ulceration with viral cytopathic change and a re-epithelializing subepidermal separation. Indirect immunofluorescence revealed intercellular IgG staining on monkey oesophagus at a titre of 1:320 consistent with pemphigus, leading to the diagnoses of pemphigus vulgaris with herpetic superinfection. Immunosuppressive treatment initially led to improvement; however, disease subsequently recurred as extensive genital erosions. We diagnosed atypical herpes simplex virus infection and oral candidiasis, discontinued all immunosuppressive medications, and initiated antiviral and antifungal therapy. Dramatic resolution was observed and the patient has remained free of disease for 13 months while taking only prophylactic famciclovir.