Erythroderma with pemphigus immunofluorescence. An erythrodermic variant of pemphigus?

A 79-year-old woman had suffered from a severe pruritic eruption for 2 year s which worsened whenever she was given nonsteroidal anti-inflammatory drug s (NSAIDs). Treatment with itraconazole, 100 mg/day for 16 days, was of no benefit, while partial remission was obtained with methylprednisolone 4 mg/ day. On examination, she was in good general condition and exhibited several pru ritic polycyclic urticarial lesions (Fig. 1). In a week, from their initial localization at the trunk and limbs, her lesions spread centrifugally to e ventually involve the whole body. Oral lesions were not present. Routine laboratory tests, including those directed to the detection of a po ssible neoplasm, were normal. Eosinophils were 800/mL. Three biopsies were taken 1 week part. All revealed only a mild epidermal hyperplasia and a lym phocytic infiltrate in the superficial dermis, with some neutrophils and eo sinophils. No acantholysis or spongiosis was observed. Direct immunofluorescence (DIF) performed on lesional skin disclosed deposi ts of both immunoglobulin G (IgG) and C3 in the intercellular spaces (ICS) of the entire epidermis (Fig. 2), and deposits of both IgM and C3 in the ve ssel walls. Three serum specimens were taken simultaneously with biopsies t o detect anti-ICS antibodies. Anti-ICS antibodies were not found in the ser um by indirect immunofluorescence (IIF) with monkey esophagus as substrate and by immunoblotting (IB) on epidermal extract. Because of the DIF features, the patient was diagnosed as having pemphigus and given 2 mg/kg/day prednisone. The lesions cleared after 1 month. During disease remission. however, IIF became positive disclosing IgG anti-ICS an tibodies at a serum dilution of 1/40 and. 6 months later, when the patient was taking 5 mg/day prednisone, the IgG titer rose to 1/80, After a further 2 months, when the patient was in clinical remission, IIF was again negati ve.