Diagnosis: Fixed drug reaction
Description: Fixed drug eruption induced by trimethoprim-sulfamethoxazole
Morphology: Plaque
Site: Buttocks
Sex: M
Age: 20
Type: Clinical
Submitted By: Shahbaz Janjua
Differential DiagnosisHistory: The lesions would recur in the same area in fixed drug eruptions when the patient is rechallenged by the same offending agent. Round to oval well demarcated plaques with a vilaceous hue are characteristic. The lesion which occur 30 min to 8 hours after exposure to the offending agent may involve periorbital and perioral area but the most commonly involved areas are genitalia, hands, and feet. Drugs that may cause fixed drug reaction include acetaminophen, anti convulsants, NSAIDs, barbiturates, benzodiazepines, dapsone, metronidazole, oral contraceptives, penicillins, sulphonamides and tetracyclines.