Prevalence Estimates for Pemphigoid in the United States: A Sex-adjusted and Age-adjusted Population Analysis

Background: The burden of the pemphigoid group of autoimmune blistering diseases is poorly understood.

Objective: To estimate standardized overall and sex-specific, age-specific, and race-specific prevalence estimates for pemphigoid among adults in the United States.

Methods: Cross-sectional analysis of electronic health records data for a demographically heterogeneous population-based sample of >55 million patients across all 4 census regions.

Results: Overall pemphigoid prevalence was 0.012%, or 12 pemphigoid patients/100,000 adults. Prevalence of pemphigoid among those aged ≥60 years was 0.038%, or 37.7 cases/100,000 adults. Prevalence increased ∼2-fold within each successive age group and was highest among patients aged ≥90 years (123.6 [95% CI 115.2-132.5] cases/100,000 adults). Adjusted prevalence in women was 12.7 (95% CI 12.3-13.2) cases/100,000 adults, slightly more than that in men (11.0 [95% CI 10.5-11.6] cases/100,000 adults). Adjusted prevalences were similar for blacks (15.4 [95% CI 14.0-17.0] cases/100,000 adults) and whites (13.5 [95% CI 13.0-13.9] cases/100,000 adults).

Limitations: Analysis of electronic health data might result in disease misclassification.

Conclusion: Pemphigoid is rare in the United States. Patients aged ≥60 years comprise the majority of cases.