Dimenhydrinate-induced Fixed Drug Eruption in Adult Woman: A Case Report

Dimenhydrinate is an H1 antihistamine of the ethanolamine class used to prevent and treat motion sickness due to its significant anticholinergic, antiserotoninergic, and sedative properties. Drug reactions to dimenhydrinate are rare, with only three reported cases of fixed drug eruption (FDE) following its ingestion recorded in the MEDLINE database from 2000 to April 2024. This case report presents a 40-year-old housewife who arrived at the emergency room with severe pain in both legs and multiple plaques on her back and upper arms after taking a second dose of 50 mg dimenhydrinate for nausea and abdominal pain. Approximately one month prior, she experienced a similar but less severe reaction after taking the same drug. Examination revealed well-demarcated dark purple plaques, 4-5 cm in diameter, with no itching or pain. The patient was diagnosed with FDE based on clinical findings. The lesions improved after one week of intravenous methylprednisolone (62.5 mg daily) during hospitalization, along with discontinuation of dimenhydrinate. This case highlights the importance of recognizing rare drug reactions like FDE in patients using common medications and underscores the need for prompt diagnosis and treatment.