Erythroderma with generalized lymphadenopathy induced by phenytoin

A 40-year-old man developed a generalized erythematous rash, fever, and systemic lymphadenopathy after treatment for two months with anticonvulsants including phenytoin. Laboratory examinations revealed increased white blood cell counts with eosinophilia, abnormal liver function, and increased gammaglobulin levels. A lymphocyte stimulation test showed a significant stimulation index for phenytoin. Skin biopsy findings were nonspecific cellular infiltrates in the upper dermis whereas in lymph nodes the normal architecture was replaced by massive cellular infiltrates consisting largely of lymphocytes, immunoblasts, and eosinophils suggesting a pattern of phenytoin lymphadenopathy. No malignant changes were noted. Phenytoin was discontinued and after a two-month treatment with oral corticosteroids, all manifestations had nearly subsided. However, the patient should be carefully followed up since phenytoin occasionally induces lymphoproliferative states including malignant lymphoma even after cessation of the medication.