Diphenylhydantoin sodium is a standard drug in the treatment of convulsive disorders. Numerous untoward reactions have been reported. Lymphadenopathy related to drug-induced hypersensitivity has occurred. A yound woman undergoing treatment for seizures developed a large, tender, localized neck mass, associated with trismus, spasmotic torticollis, fever, eosinophilia, and skin rash. She was thought to be suffering from a deep cervical fascial space abscess. Symptoms subsided rapidly after elimination of anticonvulsant medication.