Moderate-to-Severe Alopecia Areata Patients More Likely Than Mild Cases to Develop Eczema

Individuals that have moderate-to-severe alopecia areata (AA) have both higher rates of incidence and prevalence of moderate-to-severe atopic dermatitis (AD) versus individuals with mild alopecia, according to recent late-breaking data presented at the 2024 Revolutionizing Atopic Dermatitis (RAD) 2024 Annual Meeting in Chicago.¹

Prior research had suggested that those with alopecia areata have been at greater risk of developing atopic dermatitis, interchangeably referred to here as eczema. Despite such data, information highlighting eczema’s real-world prevalence as well as the incidence of moderate-to-severe disease in those with alopecia had not previously been developed.

To address this lack of information, investigators led by Arash Mostaghimi, MD, MPH, of Brigham and Women's Hospital, explored the incidence and real-world prevalence of comorbid atopic dermatitis among such individuals. They did so by accessing a US administrative claims database.

Study Design

Mostaghimi and colleagues’ trial design was retrospective, assessing claims data drawn from the Merative Marketscan Commercial Claims and Encounters database on individuals in the 12 years and older age bracket who were also given a new diagnosis of alopecia areata between January 2017 - July 2023. These subjects had to have continuous insurance coverage for 5 total years in order to be eligible for the study, and this had to precede their diagnosis and include a single inpatient or 2 outpatient alopecia-related claims.

Participants’ severity of alopecia was assessed within half a year after their diagnosis. Those diagnosed with alopecia universalis or alopecia totalis, or those given oral corticosteroids, systemic immunomodulators, other systemic agents, or phototherapy were labeled as having moderate-to-severe disease. Those labeled as severe cases were done so by diagnoses of alopecia universalis or alopecia totalis.

The research team defined moderate-to-severe atopic dermatitis by predetermined criteria in addition to claims recorded for phototherapy, high-potency topical corticosteroids, dupilumab, medium-potency topical corticosteroids, systemic immunosuppressants, topical tacrolimus, or oral/parenteral corticosteroids. Prevalence of eczema was tracked over 5 years beforehand, and incidence was monitored from 7 months after alopecia diagnosis through to the conclusion of subjects’ continuous enrollment.

The team utilized the Cox proportional hazards model to evaluate participants’ risk of eczema development if they had alopecia areata, with findings being adjusted for sex, age, Charlson Comorbidity Index (CCI), obesity, and geographic area.

Findings

The investigators found that 10,863 of those in the claims database met their criteria for inclusion, adding that 9507 finished out a minimum of 6 months of follow-up after their diagnosis. They reported that 7087 had mild alopecia, 2420 moderate-to-severe, and 491 very severe.

The research team identified the single-year period prevalence of AA in the US was 0.16%. Among the eligible patients, 63.0% were female, with an average age of 40.4 years and an average CCI of 0.7.

The team found that atopic dermatitis’ 5-year prevalence among such individuals had been 3.1% for any cases and 2.3% for moderate-to-severe disease. Individuals with moderate-to-severe alopecia had a prevalence of 4.8% for any disease and 4.2% for moderate-to-severe cases. Lifetime prevalence of any atopic dermatitis among all eligible alopecia patients and individuals with moderate-to-severe alopecia was shown to be 11.9% and 14.6%, respectively.

The investigators noted that incidence rates of atopic dermatitis were 4 per 1000 person-years for mild alopecia cases, 7 per 1000 person-years for cases which were moderate-to-severe alopecia, and 6 per 1000 person-years for those labeled as very severe. The team added that the average time to diagnosis of eczema post-alopecia had been shown to be about 2 years across all types of severity.

The research team concluded that subjects’ adjusted hazard ratio for developing atopic dermatitis had been 1.63 (95% CI 1.01, 2.64) for those with moderate-to-severe alopecia versus those with mild disease. This research adds to the growing body of information on trends among patients with alopecia areata.²

References

1. ^{Mostaghimi A, Armstrong A, Bunick C, et al. Prevalence and incidence of atopic dermatitis in patients with alopecia areata in the United States: a population-based study. Revolutionizing Atopic Dermatitis (RAD) 2024 Annual Meeting June 8 – 10, 2024. Chicago, IL.}
2. ^{Smith T. Support Groups for Alopecia Areata: Spotlighting Trends Among Patients in Attendance. HCPLive. February 12, 2024. https://www.hcplive.com/view/support-groups-for-alopecia-areata-spotlighting-trends-among-patients-in-attendance. June 12, 2024.}