Pemphigus foliaceus and oral lichen planus in a patient with systemic lupus erythematosus and thymoma.

A 49-year-old woman with systemic lupus erythematosus, and a history of thymoma and chronic white plaques of the oral mucosa, developed a blistering eruption which was diagnosed as pemphigus foliaceus based on clinical, histological and direct immunofluorescence findings. However, the white plaques had both the clinical and histological features of lichen planus, as well as intercellular antibodies suggestive of pemphigus. Such conditions in combination have been documented previously, but this is believed to be the first report of the coexistence of all four in one individual. The common mechanism underlying these four conditions may well be an immunological disturbance.