To assess risk factors for adult Still's disease (ASD).
A matched case-control study of 60 patients with ASD and 60 same sex siblings closest in age was conducted. Subjects were recruited from cohorts in Eastern Canada, Pittsburgh, and the Arthritis, Rheumatism, and Aging, Medical Information Systems (ARAMIS). A questionnaire was used to obtain data on demographic characteristics, education, income, occupation, exposure to toxic substances, stress, and medical history.
116 patients with ASD were identified, of which 104 participated. 86 identified same sex siblings, of which 60 replied. When compared to same sex siblings, ASD patients were similar with respect to education and occupation but had a trend to higher median income. There were no significant associations of ASD with smoking, alcohol consumption, individual toxic substances, vaccination, blood transfusion, minor or major surgery, pregnancy, or diet in the year preceding disease onset. There were no significant associations with tonsillectomy or adenoidectomy, appendectomy, asthma, hay fever, allergy shots, or pregnancy at any time preceding the onset of disease. There was a statistically nonsignificant increase in a history of exposure to coal dust [odds ratio (OR) 3.0; 95% confidence interval (CI) 0.30 to 28.84], in allergy preceding the onset of disease (OR 2.67; 95% CI 0.71 to 10.05), and in oral contraceptive use in the year preceding onset (OR 2.00; 95% CI 0.18 to 22.06). Stressful life events (OR 2.56; 95% CI 1.18 to 5.52) in the year preceding onset was significantly associated with increased risk for ASD. This positive association should be treated with caution unless confirmed by a separate study.
This exploratory study of risk factors for ASD draws attention to stress as a potentially important risk factor, while likely excluding a considerable number of others.