Alopecia areata (AA) is a common autoimmune cause of non-scarring, patchy hair loss that often coexists with other autoimmune diseases, notably autoimmune thyroid disease (AITD). To clarify this relationship, researchers of a population-based retrospective case-control study used Israel’s Maccabi Healthcare Services database (2005–2019) to compare all individuals with AA (n=33,401; 1.3% of the covered population; mean onset age 29.9 years; 56.5% male) to sex-matched controls at a 1:2 ratio (n=66,802). Outcomes focused on AITD prevalence (Hashimoto’s disease and Graves’ disease) and odds of association using logistic regression.
AA was significantly associated with both Hashimoto’s thyroiditis and Graves’ disease. Hashimoto’s occurred in 6.93% of patients with AA versus 4.26% of controls (OR 1.67, 95% CI 1.58–1.77; p<0.01), and Graves’ in 0.93% versus 0.55% (OR 1.68, 95% CI 1.44–1.96; p<0.01). In timing analyses, Hashimoto’s preceded AA in 55% of cases and Graves’ in 75%; diagnoses were simultaneous in ~3.5%. These findings align with prior meta-analyses and nationwide studies reporting elevated AITD risk—often stronger in severe AA—and links to thyroid antibodies and shared HLA haplotypes. Despite retrospective limitations and unmeasured confounders, the study reinforces a meaningful AA–AITD association and supports further research on the clinical utility of routine thyroid screening in AA.
Reference: Wohl Y, Bentov A, Rubin R, MaruanI A, Mashiah J. Risk of autoimmune thyroid diseases in individuals with alopecia areata: A nationwide case-control study. J Dtsch Dermatol Ges. 2025 Aug 21. doi: 10.1111/ddg.15933. Epub ahead of print.
