Toxic Epidermal Necrolysis and Mortality: A Danish Cohort Study With 30 Years of Follow‐Up

Toxic epidermal necrolysis (TEN) is a rare, life-threatening dermatologic condition, typically triggered by medications. While increased short-term mortality in this group is well documented, few studies have quantified this risk over extended follow-up. We aimed to examine both short- and long-term mortality and assess whether excess mortality persists beyond the acute phase. We conducted a nationwide, register-based matched cohort study using Danish health registries. Patients with a first-time hospital diagnosis of TEN between 1995 and 2024 were included and matched 1:100 on age and sex with population controls. Short-term mortality (30- and 90-day) was calculated, and long-term mortality was assessed overall and in a landmark analysis restricted to 2-year survivors with newly matched controls. We identified 145 individuals hospitalized with TEN and matched them to 14 500 population controls. The mean age was 56 years, and half were female. Short-term mortality was high, with 28% dying within 90 days. Median survival was 4.77 years (95% CI: 2.02-9.46) for TEN patients versus 25.96 years (95% CI: 25.19-27.20) for controls. Two years after diagnosis, TEN patients still had almost triple the mortality risk compared to controls (HR 3.30; 95% CI: 2.34-4.66). Excess mortality was also observed among patients without any recorded comorbidities at the time of diagnosis, indicating that the increased risk was not solely attributable to preexisting health conditions. Most deaths were due to natural causes; fewer than five were attributed to unnatural or unknown causes. In conclusion, this study quantifies the long-term reduction in survival following TEN. Our estimates captured the real-world excess mortality burden of TEN, arising from the acute disease, sequelae, or comorbidities, thus providing a clinically relevant picture of long-term prognosis. The increased mortality risk was not explained by baseline comorbidity alone, underscoring that TEN itself contributes to a poorer long-term prognosis.