A case of generalized bullous fixed drug eruption mimicking Stevens-Johnson syndrome

ABSTRACT Introduction: Generalized bullous fixed drug eruption (GBFDE) is a rare variant of fixed drug eruption (FDE) and has a clinical picture of dark purplish erythematous patches accompanied by bullae that break easily, leaving large erosive lesions. The clinical picture can resemble Stevens-Johnson syndrome/toxic epidermal necrolysis (SJS/TEN), so that it often causes difficulties in establishing the diagnosis. This case report aimed to describe the GBFDE that mimics SJS. Case: A 47-year-old man with complaints of dark red spots accompanied by multiple blisters. The patient has a history of metamizole allergy in the form of dark spots on the waist. On dermatological status, dark purplish erythema patches, bullae, and erosions. A positive Nikolsky sign and mucosal involvement were found. The patient was hospitalized with a diagnosis of GBFDE and was given systemic steroids. No new lesions were found, and significant improvement was seen. Discussion: In this case, GBFDE has a clinical appearance similar to SJS/TEN because there was detachment of a large area of skin and mucosal involvement. However, the history of hyperpigmented patches due to past drug reactions, description of the suspected drug consumption with the onset of complaints, and minimal systemic involvement led to the diagnosis of GBFDE. Based on the Narajo scale, the most suspected drug is metamizole, but this cannot be proven until there is a positive result on the drug patch test. Conclusion: Differentiating between GBFDE and SJS/TEN can be a challenge, but it is crucial because GBFDE has a better prognosis than SJS/TEN.