Immune-mediated diseases and subsequent risk of alopecia areata in a prospective study of US women.

INTRODUCTION: Alopecia areata (AA) is the most common form of immune-mediated hair loss. Studies have begun to establish the most frequent comorbid diseases of AA; however, results have been inconsistent with few prospective studies. METHODS: A total of 63,692 women in the Nurses' Health Study, 53-80 years, were prospectively followed from 2002 to 2014 to determine whether history of immune-mediated disease was associated with AA risk. Hazard ratios (HRs) and 95% confidence intervals (CIs) for AA in relation to immune-mediated conditions were computed using Cox proportional hazard models, adjusted for AA risk factors. RESULTS: 133 AA cases were identified during follow-up. Personal history of any immune-mediated disease was associated with increased AA risk (HR 1.72, 95% CI 1.24-2.37). History of systemic lupus erythematosus (HR 5.43, 95% CI 2.11-13.97), multiple sclerosis (HR 4.10, 95% CI 1.40-11.96), vitiligo (HR 3.13, 95% CI 1.08-9.10), psoriasis (HR 2.01, 95% CI 1.00-4.03), hypothyroidism (HR 1.88, 95% CI 1.30-2.71), and rheumatoid arthritis (HR 1.66, 95% CI 1.09-2.52) were associated with increased AA risk. History of inflammatory bowel disease or Graves' disease/hyperthyroidism was not significantly associated with AA risk. CONCLUSIONS: In this prospective study, personal history of immune-mediated diseases either individually or overall was associated with increased AA risk.