Increased risk of bullous pemphigoid in male and very old patients: A population-based study on incidence.

No data are available on gender- and age-specific incidences for bullous pemphigoid (BP). The aim of this study was to calculate incidences for different gender- and age-strata and to assess risk differences between these strata in BP. A retrospective population-based cohort was recruited from all patients diagnosed with BP in 2 well-defined regions of Germany. The average population number was 1.7 million, and the observation period was 9 years (1989-1997). Incidences were calculated as newly diagnosed cases for a population of 1 million per year. Confidence intervals (CI) were estimated based on a Poisson distribution. For evaluation of risk between different age and gender strata a Poisson regression analysis was used. The highest incidence was calculated for individuals older than 90 years, with 398 (CI: 360, 439) new cases of BP per 1 million residents for men, and 87 (CI: 70, 108) new cases per 1 million residents for women. Risk (95% CI) was 1.9 (1.3, 2.9) fold higher in men than in women. In addition, the risk for BP was increased for patients above the age of 60 years. The highest risk was found for patients older than 90 years. For this age group, the risk was 297 (CI: 107, 826) fold higher than in patients 60 years of age and younger. Men are affected by BP almost twice as often as women. The risk for BP increases rapidly beyond the age of 60 years. Because the structure of the European population is shifting towards the aged, more people are expected to suffer from BP in the coming decades.