Celiac risk doubles in patients with alopecia areata: a nationwide case -control study.

Both alopecia areata (AA) and celiac disease are common immune-mediated diseases. Despite accumulating evidence of bi-directional associations between the two disorders, data remains unclear and inconsistent. In this study we explored the association between alopecia areata and celiac disease in a large representative population cohort. Patients with alopecia areata diagnosed during 2005-2019 were compared with age and gender matched healthy controls for celiac autoimmunity. A total of 33,401 patients with alopecia areata and 66,802 controls were included in the analysis. Overall, 754 patients (0.85) had celiac disease. Compared to controls, celiac prevalence increased twofold among AA patients (1.1% Vs 0.6%, Odds ratio (OR) 1.95, 95% Confidence Interval (CI) 1.69-2.25). Higher prevalence rates were observed among all age groups, with the highest risk in AA patients older than 40 years and older. Alopecia areata may be associated with a significant increased risk for celiac disease, suggesting early diagnostic and preventive measures.