Alopecia areata linked to higher autoimmunity, inflammation and mood disorders

The study is published in the Journal of Dermatology.

Alopecia areata patients experience an increased burden of autoimmune and inflammatory diseases and mental health conditions that may negatively impact the quality of patient's life. There needs to be more data regarding the burden of comorbidities on US patients with AA and the clinical subtypes alopecia totalis (AT) and alopecia universalis (AU) than those without AA.

In the present study, researchers did a retrospective cohort study to assess the incidence rates and prevalence of AA and its clinical subtypes and examine the autoimmune and inflammatory disease and mental health condition diagnosis burden in US patients with AA and a matched cohort without AA using Optum Clinformatics Data Mart database.

The study results are:

• The selected patients were aged ≥12 years enrolled between October 1, 2016, and September 30, 2020.
• These had two or more AA diagnosis codes for the AA cohort. Three patients without AA were age-, sex-, and race-matched to each patient with AA.
• There were 8784 patients with AA (599 with AT/AU), and 26 352 matched patients without AA were included.
• The incidence rate of AA was 17.5 per 100 000 person-years.
• The prevalence rate of AA was 54.9 per 100 000 persons.
• AA patients had a higher prevalence of autoimmune and inflammatory diseases than the matched non-AA cohort.
• The findings on allergic rhinitis, asthma, atopic dermatitis and psoriasis were 24.0% vs 14.5%, 12.8% vs 8.8%, 8.3% vs 1.8% and 5.0% vs 1.6%, respectively.
• There were higher proportions of anxiety (and major depressive disorder in AA patients, constituting 30.7% vs 21.6% and 17.5% vs 14.0%, respectively.
• Patients with AT/AU had a greater prevalence of autoimmune and inflammatory disease and mental health conditions than patients with non-AT/AU AA.

The study limitations were the inherent design of retrospective database analysis and the overestimation of the difference in comorbidities.

The study's strength includes examining large cohorts, using a strict cutoff of two or more AA diagnosis codes for cohort entry, and evaluating the burden in patients diagnosed with specific AT/AU clinical subtypes.

Researchers concluded that the IR of AA was 17.5 per 100 000 PY, and the prevalence was estimated at 54.9 per 100 000 persons.

More AA patients were diagnosed with autoimmune and inflammatory diseases and mental health conditions than those without AA.

AT/AU patients experienced a higher prevalence of autoimmune and inflammatory diseases and mental health conditions than patients without AA and without AT/AU AA.

Being aware of these associations could help physicians better assist patients with AA through appropriate comorbidity screenings and treatment management, potentially before progression to more extensive clinical subtypes of AA or the development of mental health conditions related to AA diagnosis.

Further investigations are warranted to add more research in this context.

As acknowledged, the study received funding from Pfizer.

Further reading:

https://onlinelibrary.wiley.com/doi/10.1111/1346-8138.16839