Immune-Mediated and Psychiatric Comorbidities Among Patients Newly Diagnosed With Alopecia Areata.

IMPORTANCE

Alopecia areata (AA) has been associated with multiple comorbidities, yet information regarding the timing of comorbidity development after AA diagnosis is limited.

OBJECTIVE

To evaluate the prevalence and new-onset incidence of psychiatric and autoimmune comorbidities in patients with AA in the US.

DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort analysis used data collected from January 1, 2007, to April 30, 2023, from the Merative MarketScan Research Databases, which contains medical and drug claims data from more than 46 million patients in the US. Data from adolescent and adult patients (aged 12-64 years) diagnosed with AA and patients without AA (ie, controls) were evaluated. For some analyses, patients with AA were matched (1:4) to controls based on sex, age, and geographic region.

MAIN OUTCOMES AND MEASURES

Prevalence (at the time of AA diagnosis) and incidence (new onset after AA diagnosis) of psychiatric and autoimmune diseases were reported as percentage of patients. Risk of developing a new-onset psychiatric or autoimmune disease after AA diagnosis was calculated as adjusted hazard ratios (AHRs) with 95% CIs.

RESULTS

At baseline, 63 384 patients with AA and 3 309 107 without AA were identified. After matching, there were 16 512 and 66 048 patients in the AA and control groups, respectively, with a mean (SD) age of 36.9 (13.4) years and 50.6% of whom were female. Compared with the unmatched controls, patients with AA had higher prevalence of psychiatric (30.9% vs 26.8%; P < .001) and autoimmune (16.1% vs 8.9%; P < .0001) comorbidities at AA diagnosis; incidence was also higher in patients with AA (without history of these comorbidities) vs the matched control group. Patients with AA vs controls had a significantly higher risk of developing a psychiatric (AHR, 1.3; 95% CI, 1.3-1.4) or autoimmune (AHR, 2.7; 95% CI, 2.5-2.8) comorbidity.

CONCLUSIONS AND RELEVANCE

In this cohort study, patients with AA had a higher prevalence of autoimmune and psychiatric comorbidities at AA diagnosis and demonstrated an elevated risk of new-onset autoimmune and psychiatric comorbidities after their diagnosis. These data highlight the most common comorbidities among patients with AA and may help physicians counsel and monitor patients newly diagnosed with AA.