Incidence Rates of Infections, Malignancies, Thromboembolism, and Cardiovascular Events in an Alopecia Areata Cohort from a US Claims Database.

INTRODUCTION: Alopecia areata (AA) is an autoimmune disease with an underlying immuno-inflammatory pathogenesis. Treatments can include systemic corticosteroids and immunomodulators (such as Janus kinase inhibitors); these medications may be associated with a risk of some adverse events. However, large-scale observational studies of baseline incidence rates (IRs) of infection, cardiovascular disease, malignancy, and thromboembolism in US patients with AA, including those with alopecia totalis or alopecia universalis (AT/AU), are limited. This real-world, US claims-based study aimed to estimate the incidence of events in patients with AA compared with matched patients without AA.

METHODS: Patients aged ≥ 12 years enrolled in the Optum Clinformatics Data Mart database from 1 October 2016 to 30 September 2020, with ≥ 2 AA diagnosis codes were included in the AA cohort. Patients without AA were age-, sex-, and race-matched 3:1 to patients with AA. Baseline comorbidities were evaluated during the 12-month period pre-index date. Incident cases of serious/herpes infections, malignancies, major adverse cardiovascular events (MACE), and thromboembolic events were evaluated post-index date. Data are presented using descriptive statistics, proportional percentages, frequencies, and IRs (calculated with 95% CI).

RESULTS: Overall, 8784 patients with AA, 599 of whom had AT/AU, were matched to 26,352 patients without AA. IRs per 1000 person-years among the AA and non-AA cohorts, respectively, were 18.5 and 20.6 for serious infections, 19.5 and 9.7 for herpes simplex infections, 7.8 and 7.6 for herpes zoster infections, 12.5 and 11.6 for primary malignancies, 16.0 and 18.1 for MACE, and 4.9 and 6.1 for venous thromboembolisms. Compared with patients with non-AT/AU AA, patients with AT/AU largely had higher IRs for most baseline comorbidities and outcome events evaluated.

CONCLUSION: Patients with AA had a higher IR of herpes simplex infection than the matched non-AA cohort. Patients with AT/AU generally had higher rates of outcome events than patients without AT/AU.