Mortality of bullous pemphigoid in Switzerland: a prospective study

Background Bullous pemphigoid (BP) is the most common autoimmune subepidermal blistering disease of the skin and has been associated with a significant morbidity and an increased mortality rate. Objectives Our aims were: (i) to evaluate the mortality rate of BP in Swiss patients during the first 3 years after the diagnosis of BP, as the primary endpoint; and (ii) to compare this mortality rate with that of the general Swiss population and determine prognostics factors, as secondary endpoints. Methods All new cases of BP diagnosed in Switzerland between 1 January 2001 and 31 December 2002 were collected prospectively by means of a standardized data collection form. After collection of the data, the treating physicians were asked to specify the course and evolution of the disease. In total, 115 patients were included in our study. Results The 1-, 2- and 3-year probability of death were 20.9%, 28.0% and 38.8%, respectively. The mortality rate of patients with BP was three times higher than that of age-and sex-matched members of the general Swiss population. Besides age, the presence of neurological diseases at diagnosis was associated with increased mortality in multivariate analysis. Conclusion This is the first prospective study analysing the mortality rate of BP in an entire country. The calculated mortalities are in the lower range of those reported in previous European studies. However, in line with the latter, our findings confirm a high case-fatality rate for BP, with an increased 1-year mortality rate compared with the expected mortality rate for age-and sex-adjusted general population.