Incidence and mortality of bullous pemphigoid in north-east Poland (Podlaskie Province), 1999-2012: a retrospective bicentric cohort study

Background Bullous pemphigoid (BP) is the most frequently encountered autoimmune blistering disorder, affecting mainly elderly population. The aim of the study was to assess the incidence of BP in Podlaskie Province (north-east Poland) in 1999-2012, socio-demographic characteristics and mortality of patients with BP. Methods The number of newly diagnosed (in two regional hospitals) cases of BP per million inhabitants of the province in consecutive years was calculated and analysis of age, sex, and residency of patients performed. Results A total of 122 cases of BP were diagnosed (in 52 males and 70 females). The average annual incidence was 7.38 +/- 3.51 per million inhabitants: 5.70 +/- 4.16 and 9.26 +/- 4.40 in urban and rural areas, P < 0.05, respectively, and had an increasing trend over the period analyzed. Age of patients with BP was 74.18 +/- 12.12. The incidence among men and women over 75 years of age was 86.67 +/- 61.39 and 51.49 +/- 41.44, P < 0.05, respectively. The 1-year mortality of patients was 32.35 and 18.42% (P < 0.05) in men and women, respectively. Overall mortality was 36.11%. Conclusions The incidence of BP in Podlaskie Province is almost twice as high among residents of rural than urban areas, and in males than females in advanced age. The results suggest that the incidence of BP will be increasing in an aging society, as will its impact on the quality of life of the population.