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

Abstract

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 1 093 176 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 100 000; 95% CI, 263-335) and 40 to 49 (270 per 100 000; 95% CI, 240-303) years. The highest standardized prevalence was observed among Asian patients (414 per 100 000; 95% CI, 306-548), followed by patients reporting another race or multiple races (314 per 100 000; 95% CI, 266-368), Black (226 per 100 000; 95% CI, 199-255), and Hispanic/Latino (212 per 100 000; 95% CI, 129-328) patients. White patients had the lowest standardized prevalence (168 per 100 000; 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.

Characterizing Epidemiology and Burden of Disease in Alopecia Areata—Making It Count

“…It is encouraging that Sy et al and Mostaghimi et al coalesced around similar prevalence estimates despite using different data sources. When using large-scale big data like aggregate EHR data and health care claims, it is critical to interrogate who is actually included and who is missing from such data sets to properly contextualize any epidemiologic estimates.…”

“…Sy et al and Mostaghimi et al take different methodological approaches, using big data to estimate the burden of AA. In a 1-year cross-section in 2019 using EHR data, Sy et al evaluated more than 1 million patients, with a total of 1812 cases of AA, and estimated the prevalence of AA to be 0.18% among adults and 0.10% among children and adolescents.…”

“…Sy et al and Mostaghimi et al take different methodological approaches, using big data to estimate the burden of AA. In a 1-year cross-section in 2019 using EHR data, Sy et al evaluated more than 1 million patients, with a total of 1812 cases of AA, and estimated the prevalence of AA to be 0.18% among adults and 0.10% among children and adolescents. Using claims data, Mostaghimi et al analyzed more than 13 000 affected patients per year for 4 years and described increasing prevalence of AA from 2016 to 2019, with prevalence reaching 0.22% in 2019.…”

“…In contrast, Sy et al leverage an EHR-based database to estimate prevalence of AA and characterize these conditions across racial and ethnic groups. There is substantial depth gained, such as patient demographic characteristics when using such approaches, which can provide a clearer snapshot for potential inequities.…”

“…In the last several years, studies of the National Alopecia Areata Foundation registry and the National Ambulatory Medical Care Survey database have characterized the population of patients with AA in the US as predominantly female and people of racial and ethnic minority groups, including Asian, Black, and Hispanic individuals. In this issue of JAMA Dermatology , the 2 studies by Sy et al and Mostaghimi et al undertake the task of estimating prevalence for AA and the racial and ethnic makeup of the AA population using novel claims-based and electronic health care record (EHR)–based methods.…”