Survival Following Steroid-Based Therapy in a Case of Penicillin-Induced Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis Overlap.

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are life-threatening mucocutaneous reactions with mortality rates strongly correlated with disease severity. We report the case of a 47-year-old Mestizo man in Nicaragua with penicillin-induced SJS/TEN overlap syndrome (body surface area involvement: 10%-30%, score of toxic epidermal necrolysis, SCORTEN: 4, and predicted mortality: 58%). The patient developed mucosal erosions, hemorrhagic crusting, and disseminated erythematous plaques following exposure to amoxicillin and dicloxacillin (penicillin-class antibiotics). Initial misdiagnoses delayed care, but hospitalization prompted early intravenous dexamethasone, fluid resuscitation, topical corticosteroids, and immediate discontinuation of the offending agents. Epidermal detachment halted within 72 hours, with complete reepithelialization by day 10. Transient hyperglycemia resolved spontaneously, and the patient survived without infections or sequelae, contrasting with the SCORTEN-predicted mortality. This outcome supports early immunomodulation to mitigate cytokine-driven necroptosis, challenging historical concerns about corticosteroid risks. Limitations include the single-case design, absence of histopathology, and lack of human leukocyte antigen allele screening for pharmacogenomic insights. The case underscores the efficacy of prompt corticosteroids in high-risk SJS/TEN linked to penicillin-class drugs, emphasizing drug-specific vigilance and discontinuation. It highlights the need for population-specific SCORTEN calibration, pharmacogenomic integration, and publication of rare cases to enhance regional epidemiological understanding.