Kronzer VL, et al. - In this case-control study, 1,023 cases of rheumatoid arthritis (RA) were estimated to analyze the correlations between RA and asthma, passive smoke exposure, and age of starting smoking. Investigators found 1,023 cases of RA (175 incident) within a single-center biobank population. RA had an association with history of allergic disease (especially food allergy) in both the full and incident cohorts. No relationship between passive smoke exposure at home or work and RA was noted. They also reported an association of urban environment, and passive smoke exposure, asthma with RA in the full cohort but not the incident cohort, after adjusting for allergies.