Autism Spectrum Disorder Associates With Higher Rate of Alopecia Areata

There is an association between autism spectrum disorder (ASD) and alopecia areata (AA), according to a letter to the editor published in Journal of the American Academy of Dermatology.

Researchers from Yonsei University Wonju College of Medicine in South Korea conducted this study using data from the National Health Insurance Service database. Patients (n=19,084) who were born in South Korea after 2002 and had 3 or more documented health care visits with a diagnosis of ASD between 2002 and 2019 were matched in a 1:5 ratio with the general population (n=95,420). Rates of AA diagnoses and AA subtypes were evaluated between cohorts.

The ASD and control cohorts comprised 21.8% and 21.8% girls, they were aged 13.4±2.3 and 13.4±2.3 years at the index date, 10.8% and 3.9% had Medicaid insurance (P <.001), 40.1% and 36.0% of patient families were in the highest income level (P <.001), and 67.9% and 63.0% lived in a metropolitan area (P <.001), respectively.

Among participants in the ASD cohort, the average age of onset was 5.3±3.6 years and 25.9% were diagnosed with AA prior to ASD.

Overall, AA onset occurred at a similar age among those in the ASD and control cohorts (mean, 8.7 vs 8.9 years; P =.288), respectively. A total of 371 and 1424 of participants in the ASD and control cohorts were diagnosed with AA for incidence rates of 13.61 and 10.43 per 10,000 person-years, respectively.

In the fully adjusted model accounting for thyroid diseases, autoimmune hepatitis, and vitamin D deficiency, ASD was associated with higher rates of AA (adjusted hazard ratio [aHR], 1.238; 95% CI, 1.100-1.395) and patchy alopecia areata (aHR, 1.251; 95% CI, 1.108-1.412), but not alopecia totalis or universalis (aHR, 0.965; 95% CI, 0.540-1.726) compared with the general population. No associations were observed between ASD and benign skin tumor (aHR, 0.926; 95% CI, 0.856-1.002) or epidermal cyst (aHR, 0.974; 95% CI, 0.864-1.099) risk.

Study limitations include a lack of generalizability of the findings to other ethnicities.

Study authors conclude, “[P]atients with ASD had an independently higher risk of AA than individuals without ASD. Considering the pathogenesis of AA, this association may be attributed to the links among autoimmunity, immune dysregulation, and genetic background. […] However, further research is needed because of the complex and multifaceted nature of ASD.”