Overall and Racial and Ethnic Subgroup Prevalences of Alopecia Areata, Alopecia Totalis, and Alopecia Universalis

Key PointsQuestionWhat is the prevalence of alopecia areata (AA) and its subtypes overall and among racial and ethnic subgroups in the US? FindingsIn this cross-sectional study, 1812 of the 1093176 eligible patients had at least 1 code for AA; overall age- and sex-standardized prevalences among adults, children, and adolescents were observed to be 0.18% and 0.10%, respectively. Relative to White patients, standardized prevalence ratios for Asian, Black, and Hispanic/Latino patients were 2.47, 1.35, and 1.26, respectively; cases of alopecia totalis and alopecia universalis comprised approximately 9% of patients diagnosed with AA. MeaningThe findings of this study suggest that Americans, particularly persons of color, have a significant burden of alopecia areata. This cross-sectional study examines the prevalence of alopecia areata, alopecia totalis, and alopecia universalis overall and among racial and ethnic groups in the US. ImportancePrevalences of alopecia areata (AA), alopecia totalis (AT), and alopecia universalis (AU) are poorly established. ObjectiveTo estimate overall and subgroup prevalences of AA and its subtypes. Design, Setting, and ParticipantsThis cross-sectional study using electronic records comprising the Explorys database (Watson Health, IBM Corporation) included children, adolescents, and adults seeking healthcare across the 4 census regions in the US between January 1, 2019, and December 31, 2019. The statistical analysis was conducted between July 21, 2022, and December 22, 2022. Main Outcomes and MeasuresPrevalent cases of AA, AT, and AU. ResultsOf the 1093176 patients who met inclusion criteria, 1812 had at least 1 code for AA, 1216 female (67%) and 596 male (33%) patients. Overall age-and-sex standardized prevalences among adults and among children and adolescents were observed to be 0.18% and 0.10%, respectively. The age-standardized prevalence ratio in women to men was 1.32. Standardized prevalence was highest in those aged 30 to 39 (297 per 100000; 95% CI, 263-335) and 40 to 49 (270 per 100000; 95% CI, 240-303) years. The highest standardized prevalence was observed among Asian patients (414 per 100000; 95% CI, 306-548), followed by patients reporting another race or multiple races (314 per 100000; 95% CI, 266-368), Black (226 per 100000; 95% CI, 199-255), and Hispanic/Latino (212 per 100000; 95% CI, 129-328) patients. White patients had the lowest standardized prevalence (168 per 100000; 95% CI, 157-179) among racial and ethnic subgroups. Relative to White patients, standardized prevalence ratios for Asian, Black, and Hispanic/Latino patients were 2.47 (95% CI, 2.17-2.81), 1.35 (95% CI, 1.26-1.44), and 1.26 (95% CI, 1.03-1.55), respectively. Cases of AT and AU comprised approximately 9% of patients diagnosed with AA. Conclusions and RelevanceThe findings of this cross-sectional study suggest that there is a significant burden of AA, AT, and AU in the US in which people of color, particularly Asian Americans, appear to be disproportionately affected.

Automated summary

This cross-sectional study found that there is a significant burden of alopecia areata (AA), particularly among people of color, especially Asian Americans, in the US. Cases of alopecia totalis (AT) and alopecia universalis (AU) comprised approximately 9% of patients diagnosed with AA.