A functional dichotomy between Th1- and Th2-type immune responses has been suggested. This study was performed to investigate whether rheumatoid arthritis (RA), a disease with indications of Th1-deviated immune activation, is inversly related to atopic conditions which are Th2-mediated. Two hundred and sixty-three adult cases of RA, fulfilling the American Rheumatism Association (ARA) 1987 Revised Classification Criteria for RA, were identified in 1995 and compared with 541 randomly selected population referents. The presence of atopic manifestations was established through a postal questionnaire and by demonstrating circulating IgE antibodies to common allergens. RA was inversely associated with certain manifestations of rhinitis, which were regarded as the most reliable indicators of atopic disease in the present study. However, no negative association was seen between RA and asthma and eczema, respectively. The main results give some support for an inverse relationship between RA and rhinitis. The prevalence of circulating IgE antibodies was however similar in cases and controls, suggesting that the T-cell commitment mainly occurs in the affected organs.