Infectious complications in bullous pemphigoid: an analysis of risk factors.

Background: Infections are common in bullous pemphigoid and contribute to significant mortality.

Objectives: We sought to define the spectrum of infectious complications and to identify associated risk factors in a bullous pemphigoid cohort.

Design: A retrospective cohort study conducted at an academic medical center.

Results: In all, 97 patients were included. Infectious complications occurred in 54 patients (56%) and the median duration from diagnosis to first episode of infection was 3 months. Bacteremia occurred in 14 patients (26%) and 26 of 30 deaths (87%) were attributable to infections. On univariate analysis, significant risk factors include low Karnofsky score (<60) (odds ratio [OR] 3.5, 95% confidence interval [CI] 1.5-8.3; P < .01), high Charlson comorbidity index score (≥6) (OR 2.4, 95% CI 1.1-5.5; P = .04), and dementia (OR 4.9, 95% CI 1.5-15.8; P = .01). On multivariate analysis, low Karnofsky score and dementia remained significant with an OR of 3.3 (95% CI 1.1-10.0; P = .03) and OR of 4.2 (95% CI 1.2-14.7; P = .03), respectively.

Limitations: Limitations include potential selection bias as a result of study design and primary outcome measures focused on significant infections requiring hospitalizations. Minor infections were not included.

Conclusions: Identified risk factors for infectious complications include functional impairment and the presence of dementia, which may allow for better risk stratification and individualized treatment of bullous pemphigoid.