Stevens-Johnson syndrome and toxic epidermal necrolysis are severe cutaneous adverse reactions that are of major concern because of high mortality rates. On the basis of data collected in the RegiSCAR study, the aim was to assess risk factors (including modalities of patient management) for mortality, regardless of the cause, up to 1 year after the reaction. Within this cohort, the mortality rate was 23% (95% confidence interval (CI) 19-27%) at 6 weeks and 34% (95% CI 30-39%) at 1 year. Severity of reaction was a risk factor for mortality only in the first 90 days after onset, whereas serious comorbidities and age influenced mortality beyond 90 days and up to 1 year after onset of reaction. The risk of death for patients with identified drug cause was borderline lower than for patients with a reaction of unknown cause (hazard ratio 0.66, 95% CI 0.45-0.96). The study could not provide conclusive evidence regarding patient management. This large-scale population-based follow-up study of such patients confirmed high in-hospital mortality and revealed a remarkable number of deaths after discharge, which could mainly be attributed to severe comorbidities and older age, whereas the impact of severity of reaction on the risk of death was limited to the first few weeks.