Risk Factors for Pediatric Alopecia Areata: Clinical and Biochemical Findings from a Case – Control Study

Introduction: Alopecia areata (AA) is an immune-mediated, non-scarring hair loss disorder that can begin in childhood. Data on comorbidities and biochemical risk factors in pediatric AA remain limited. Objectives: To compare clinical comorbidities and biochemical parameters in pediatric patients with AA versus healthy controls. Methods: This retrospective, matched case-control study included 200 pediatric AA patients and 400 age- and sex-matched healthy controls. Clinical characteristics and comorbidities were obtained from patient records. Hemoglobin, ferritin, vitamin B12, and thyroid-stimulating hormone (TSH) levels were analyzed. Independent predictors were identified using multivariable logistic regression. Results: Vitiligo (3.5% vs. 0.5%; P=0.008), allergic asthma (9.5% vs. 3.8%; P=0.007), and attention-deficit/hyperactivity disorder (ADHD) (3.5% vs. 0.5%; P=0.008) were significantly more frequent in the AA group, whereas atopic dermatitis was more common but not statistically significant. Hemoglobin levels were comparable. Serum vitamin B12 233.5 (192.7–270.0) vs. 356.7 (318.7–396.8) pg/mL; P<0.001 and ferritin 14.4 (6.5–22.3) vs. 19.4 (11.6–27.0) ng/mL; P<0.001 were significantly lower, and TSH levels were also reduced (3.40 ± 1.48 vs. 3.71 ± 1.50 mIU/L; P=0.017). Multivariable analysis identified low vitamin B12 (OR = 0.964, 95% CI: 0.958–0.970; P<0.001) and low ferritin (OR = 0.965, 95% CI: 0.944–0.988; P=0.003) as independent risk factors. Conclusions: Pediatric AA is associated with vitiligo, asthma, ADHD, and reduced levels of ferritin, vitamin B12, and TSH. These findings underscore the importance of comprehensive clinical and biochemical evaluation in pediatric AA.