Risk of Death in Bullous Pemphigoid: A Retrospective Database Study in Finland

Abstract

Bullous pemphigoid (BP) is an autoimmune skin disease of elderly people, which is associated with increased mortality. The aim of this study was to investigate the standardized mortality ratio (SMR) for BP in Finland, and concomitant comorbidities and medications. This was a retrospective database study of all cases of BP diagnosed at the Department of Dermatology, Oulu University Hospital, Finland, between 1985 and 2012. A total of 198 immunologically confirmed cases of BP were found. One-year mortality was 16.7%, and SMR 7.56 (95% confidence interval (CI) 4.98–10.14). The most common comorbidities were cardiovascular diseases (76.3%) and neurodegenerative diseases (40.9%). Malignancies (8.6%) were associated with increased mortality (hazard ratio=2.4, 95% CI 1.1–5.5, p=0.047). A novel finding was that polypharmacy was very common in patients with BP, and the higher the number of drugs, the greater the mortality. In conclusion, the mortality for BP in Finland is 7.6-fold that of a reference population, and malignancies and polypharmacy are associated with increased mortality.