Lifetime incidence and healthcare disparities in alopecia areata: a UK population-based cohort study

Br J Dermatol. 2024 Nov 18;191(6):924-935. doi: 10.1093/bjd/ljae307.

Abstract

Background: Alopecia areata (AA) is an immune-mediated form of hair loss that can occur at any age, often with a significant mental health burden.

Objectives: We aimed to provide estimates of the lifetime incidence of AA, and the impacts on mental health, healthcare utilization and work-related outcomes, assessing variation across major sociodemographic subgroups.

Methods: AA cases were identified in primary care from the UK population-based Oxford-Royal College of General Practitioners Research and Surveillance Centre database (2009-2018). Lifetime incidence of AA was estimated at age 80 years using modified time-to-event models with age as the timescale, overall and stratified by sex, ethnicity, deprivation and geography. Mental health, healthcare utilization and work-related outcomes were assessed in the 2 years after AA diagnosis compared with matched unaffected controls, and stratified by the same sociodemographic subgroups.

Results: During the study period, 6961 people developed AA. Overall lifetime incidence of AA was 2.11% [95% confidence interval (CI) 2.06-2.16]. Females had a higher lifetime incidence (2.35%, 95% CI 2.28-2.43) than males (1.88%, 95% CI 1.81-1.94). Lifetime incidence was higher in those of Asian ethnicity (5.87%, 95% CI 5.51-6.24), Other (4.5%, 95% CI 3.63-5.31), Mixed (4.4%, 95% CI 3.50-5.37) and Black (3.0%, 95% CI 2.63-3.42) ethnicity, compared with White ethnicity (1.7%, 95% CI 1.68-1.80). Lifetime incidence was highest in those with the greatest deprivation: most-deprived quintile (2.92%, 95% CI 2.77-3.07) compared with least-deprived (1.68%, 95% CI 1.59-1.78). Across sociodemographic subgroups, people with AA of Black ethnicity were most likely to have anxiety (adjusted odds ratio vs. matched controls 2.92, 95% CI 1.71-4.91), and had the greatest risk of time off work (adjusted hazard ratio vs. matched controls 2.54, 95% CI 1.80-3.56).

Conclusions: AA affects around 1 in 50 people over their lifetime. The incidence and impact of AA on mental health and work outcomes is highest in ethnic groups other than White. Clinicians should be aware of the marked heterogeneity in the incidence and impact of AA, and support targeted healthcare to groups at the highest risk of alopecia and its consequences.

Plain language summary

Alopecia areata (AA) is a condition characterized by hair loss that involves the immune system. AA can develop at any age but commonly affects young adults. The symptoms are often unpredictable, and people with AA can experience distress or in some cases, mental health conditions. In this study, we investigated how the impact of AA varies between groups of people. We used electronic medical records from general practices in the UK from 2009 to 2018. We looked at how many people developed AA, their age at diagnosis, the risk of AA between females and males, and the risk between different ethnic groups, and between areas in which people lived. We found that 2 in every 100 people will develop AA across their lifetime. The risk of AA was different across ethnic groups. People from the Asian ethnic group had the greatest risk with nearly 6 cases per 100 people, compared with fewer than 2 cases per 100 people for the White ethnic group. People living in deprived or urban areas were also at higher risk of AA. We also found the impact of having AA differed between ethnic groups. People from the Black ethnic group with AA were most likely to have anxiety and most likely to have time off work certificates issued by their doctor. Overall, our study findings suggest that both the risk and impact of AA varies across the population of the UK. This information should help clinicians target support towards people experiencing the greatest burden.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Alopecia Areata* / epidemiology
  • Alopecia Areata* / ethnology
  • Child
  • Child, Preschool
  • Cohort Studies
  • Female
  • Healthcare Disparities* / statistics & numerical data
  • Humans
  • Incidence
  • Male
  • Middle Aged
  • Patient Acceptance of Health Care / statistics & numerical data
  • United Kingdom / epidemiology
  • Young Adult

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