Alopecia areata in the United States: National and state-level epidemiologic trends (2010–2021)

Summary: Background: Alopecia areata (AA) is a chronic autoimmune disorder that causes non-scarring hair loss, significantly impacting psychosocial well-being. We assessed national and state-level epidemiology of AA in the US from 2010 to 2021, stratified by age and sex. Methods: In this population-based study, we used established methods from the Global Burden of Diseases (2021) to quantify age-standardized rates for incidence (ASIR), prevalence (ASPR), and disability-adjusted life years or DALY (ASDR) per 100,000 in the US. This analysis integrates national surveys, medical records, and claims databases using Bayesian meta-regression modeling (DisMod-MR 2.1). All estimates were reported with 95% uncertainty intervals (UIs). Results: In 2021, an estimated 1.145 million individuals in the U.S. had AA (95% UI: 1.113–1.178 million), reflecting an 8% increase since 2010. Incidence reached 2.01 million cases (95% UI: 1.95–2.06 million), showing a similar 8% rise over the same period. The point prevalence of AA was 0.34%. The incidence rate in females was 2.53 times higher than in males. Incidence rates increase from adolescence, peak at 30–34 years, and then decline progressively in older adults. The ASIR, ASPR, and ASDR of AA in the U.S. declined slightly over the study period but remained significantly higher than global rates. The District of Columbia and New York had the highest rates, while Wyoming, Mississippi, and Alaska had the lowest. Conclusion: AA continues to affect a substantial portion of the US population, with distinct patterns by age, sex, and state. Hossein Akbarialiabad¹, Christopher G. Bunick², Natasha Mesinkovska⁵, Mohammad Hossein Taghrir³, Ayman Grada⁴ 1. Department of Dermatology, University of Utah Health, Salt Lake City, UT, United States. 2. Department of Dermatology, Yale University, New Haven, CT, United States. 3. Department of Dermatology, Shiraz University of Medical Sciences, Shiraz, Fars Province, Iran (the Islamic Republic of). 4. Department of Dermatology, Case Western Reserve University, Cleveland, OH, United States. 5. University of California Irvine, Irvine, CA, United States. Clinical Research: Epidemiology and Observational Research