Our study makes the BJD cover this month
What our client needed: epidemiology data on alopecia areata to support the use of new treatments.
What we delivered: the largest population-based analysis of alopecia areata ever conducted, with the latest study featured on the front cover of this months UK's leading dermatology journal.
Alopecia Areata is an immune-mediated form of hair loss, which can be distress as prognosis is unpredictable and relapse is common. In the UK around 0.5% of adults have alopecia areata, but it was not known if risk of alopecia varied sex, ethnicity or deprivation.
We sought to comprehensively evaluate disparities in alopecia areata across sociodemographic groups to identify who is most at risk and where support could best be targeted.
Using our extensive experience with UK electronic medical record databases alongside our in-house pipelines and quality control, we identified specific clinical codes to identify those with alopecia areata, and exclude other alternative diagnoses (scarring alopecia, traction alopecia, congenital alopecia, androgenetic alopecia, telogen effluvium, tinea capitis, trichotillomania, or secondary syphilis of the scalp). Alopecia areata cases were carefully matched with up to four population-based controls, on age, sex, ethnicity, and general practice to ensure well balanced cohorts. This not only helped ensure cases and controls were well matched in terms of key variables, but also minimises influence of potential differences in coding between GP practices. We identified 6,961 people who developed alopecia areata during the study period.
We used novel methods to present alopecia risk as cumulative lifetime incidence, which is an accessible way to visualise risk across the lifespan and how this differs between subgroups. We also investigated how healthcare utilisation, mental health and employment impacts varied across subgroups.
Alopecia areata affects 2 in 100 people with an overall, lifetime incidence of 2.1%. However, this risk differed markedly across ethnic groups: Asian (5.9%), other (4.5%), mixed (4.4%), black (3.0%) and white (1.7%).
We also identified that the impacts of AA also differed by ethnic group: people with alopecia areata of black ethnicity had the greatest burden of concomitant anxiety and were the most likely to have recorded time off work. Despite this, there were no clear differences between ethnic groups in the provision of specialist referrals to either dermatological or mental health services. Our findings highlight that clinicians should be particularly aware of the increased risk alopecia areata people who do not identify as white and the importance of screening and monitoring, to ascertain those who may need additional psychological support.
The findings were published in the British Journal of Dermatology, with the visual abstract used on the front cover, highlighting the importance and accessibility of the results.