Phenytoin Induced Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS): Case Report

Background: Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a rare and potentially life-threatening condition. It presents a long prodromal period, extensive rash, fever, lymphadenopathy, hematologic abnormalities (eosinophilia with or without atypical lymphocytosis), and internal organ involvement. Purpose: To describe a case of phenytoin induced DRESS syndrome, presenting diagnostic and management challenges of clinical interest. Methods: The Consensus-based Clinical Case Reporting Guideline Development (CARE) was observed for data analysis in case reports. Case Report: A 22-year-old man, using phenytoin for 60 days, sought medical attention due to fever and maculopapular cutaneous lesions. He presented lymphocytosis with eosinophilia and severe acute hepatitis 24 hours after admission day. Hepatic transaminases returned to reference levels after phenytoin withdrawal, and eosinophilia and cutaneous manifestations did not respond well to systemic steroids. A forearm biopsy showed findings suggestive of severe cutaneous adverse reaction. The patient’s microscopic and clinical characteristics meet all criteria in the scoring systems of Bocquet et al., Registry of Severe Cutaneous Adverse Reaction (RegiSCAR), and Japanese Research Committee on Severe Cutaneous Adverse Reaction (J-SCAR), being highly suggestive of DRESS syndrome very probably caused by phenytoin. The complete remission of symptoms was achieved weeks after admission. Conclusions: DRESS syndrome is a defiant reaction. Clinicians must be aware of potential causative drugs and perform a complete clinical examination using the available resources, including laboratory tests and histopathological assessment. The clinical remission relies on the withdrawal of the culprit drug. Particular attention should be given to the involvement of internal organs.