Prevalence of Pediatric Alopecia Areata Doubled in Last Decade

Leslie Castelo-Soccio, MD, PhD

A recent cohort study found that the prevalence of alopecia areata in pediatric patients across the United States had nearly doubled in the last decade, with an incidence rate of 13.6 cases per 100,000 person-years.

From 2009 to 2020, investigators found a prevalence of 0.11%across time, age, sex, race and ethnicity, and region in pediatric patients.

Current assessments of the prevalence of alopecia areata in adults range from 0.2% and 2%, but little research exists on AA prevalence and incidence in young patients.

Investigators led by Leslie Castelo-Soccio, MD, PhD, of the National Institutes of Health utilized PEDSnet to form the largest and most accurate epidemiological description of AA in children to date.

The multi-institutional clinical research network offered data from approximately 7 million children across the US. Institutions featured in the current study included the Children’s Hospital of Philadelphia, Children’s Hospital Colorado, Nationwide Children’s Hospital, Nemours Children’s Health System and Seattle Children’s Hospital.

The study cohort included patients 18 years or younger with at least 2 physician visits in any clinical setting followed by a diagnosis code for AA, or 1 dermatologist specialty visit for which AA was recorded.

Investigators reviewed 100 cases from the Children’s Hospital of Philadelphia to assess the accuracy of AA diagnosis and found a 95% positive predictive value for the diagnosis code.

Prevalence of AA was determined by the number of AA cases in each category (age, sex, race and ethnicity, etc.) divided by the prevalence denominator. Incidence was calculated by the time of observation – defined as the period from the first visit to the end of the study period- or the first occurrence of AA after the initial visit in the incidence cohort.

Finally, investigators used multivariable logistic regression to identify risk factors for development of AA.

Castelo-Soccio and colleagues recruited a total of 5801 patients with AA, 3259 of whom were female (56.2%).

Among those in the AA cohort, 2398 (41.3%) had 12 months or more of follow-up and were included in the incidence analysis. A total of 359 (6.2%) patients were Asian, 1094 (18.9%) were Black, 1348 (23.2%) were Hispanic, and 2362 (40.7%) were White.

Though the overall prevalence of AA was 0.11%, investigators observed that patients in the AA cohort were often older, female, and members of a racial and ethnic minority group compared to the full PEDSnet population.

The incidence rate over the course of the 11-year study period was 13.6 cases per 100,000 person-years, and the incidence rate by age peaked at 6 years.

Notably, incidence rates of AA were 22.8% higher in female patients than male patients, with 15.1 cases per 100,000 person years for the former and 12.3 cases per 100,000 person-years for the latter. Males were significantly less likely to receive a diagnosis of AA compared to females.

Additionally, an analysis across race and ethnicity found significantly increased rates among Asian and Black populations compared to White children, with the highest incidence rates being observed in Hispanic children.

This was considered by investigators to be among the most remarkable findings in the study.

“With these new data, efforts should be placed on increasing education in diverse communities to expand awareness about AA and access to care for children living with this disease,” the team wrote.

The study, "Evaluation of the Prevalence and Incidence of Pediatric Alopecia Areata Using Electronic Health Record Data," was published online in JAMA Dermatology.