Fatal benign phenytoin lymphadenopathy

A 71-year-old man had status epilepticus and was treated with phenytoin (Dilantin) sodium. Subsequently, an absolute eosinophilia developed, which increased and reached its zenith immediately before the patient died. At autopsy, anasarca and an interstitial nephritis characterized predominantly by eosinophils and occasional focal necrotizing arteriolar glomerular lesions were found. Portal areas also contained an eosinophilic infiltrate. It has been previously stressed that exfoliative dermatitis is often the initiating sign of an allergic hypersensitivity reaction with phenytoin therapy. In view of this, we would suggest that a potential first sign of such an underlying reaction may be the development of an otherwise unexplained absolute eosinophilia.