Intraepidermal IgA pustulosis preceding a CD30+ anaplastic large T-cell lymphoma

We report the case of a 62-year-old patient with an extracutaneous CD30+ anaplastic large T-cell lymphoma which was preceded by intraepidermal IgA pustulosis (IEAP). The clinical picture was identical to Sneddon-Wilkinson disease and histologic examination showed subcorneal pustules with slight acantholysis. Direct immunofluorescence exclusively revealed IgAK deposits on the plasma membrane of suprabasal keratinocytes. Indirect immunofluorescence and immunoelectrophoresis showed no evidence of monoclonal IgA gammopathy. IEAP responded to dapsone treatment (100 mg/day). Two months after disappearance of active cutaneous lesions, the patient developed generalized lymphadenopathy due to CD30+ anaplastic T-cell lymphoma.