Abstract: Objective: Pemphigus is a rare group of autoimmune bullous diseases yet its epidemiological data remain limited worldwide. This study aimed to quantitatively estimate the global, regional, and national epidemiological burden of pemphigus and its subtype pemphigus vulgaris (PV). Methods: We systematically retrieved epidemiological studies on pemphigus and constructed a Bayesian hierarchical linear mixed model to estimate the incidence and annual new cases of pemphigus and PV globally, regionally, and nationally. The prevalence was summarized descriptively. Results: Fifty-five studies were included. The estimated global incidence of pemphigus and PV was 4.05 (0.84-8.25) per million person-years and 3.62 (0.73-7.60) per million person-years, with approximately 32 500 and 29 000 new cases per year, respectively. The regional incidence of pemphigus varied from 1.92 per million person-years in southern Sub-Saharan Africa to 5.32 in North Africa and the Middle East. At the national level, Iran had the highest incidence (9.78 per million person-years), while Morocco had the lowest (0.70 per million person-years). A similar geographic pattern was observed for PV. Females had a consistently higher incidence globally, with a 1.36-fold difference for pemphigus (4.18 per million person-years vs. 3.07 per million person-years) and a 1.38-fold difference for PV (3.57 per million person-years vs. 2.59 per million person-years). No significant difference was found between adult and general population incidence, suggesting insufficient age-stratified data. Prevalence also showed considerable geographical heterogeneity. Conclusion: Epidemiological data on pemphigus are lacking in nearly 84% of countries worldwide, with notable disparities by sex, age, and geography. This study fills critical data gaps and provides evidence for disease surveillance and prevention.

Key words: pemphigus, pemphigus vulgaris, epidemiology, incidence, bayesian hierarchical linear mixed model