The physician questionnaire contained three questions about environmental exposures that had been previously suggested to be possibly associated with the onset of JDM [16, 17, 19, 20] . These included whether the patient had any documented infections, received any immunizations or took any medications (including vitamins, minerals, herbal preparations and dietary supplements) within 6 months before illness onset. The questionnaire also included an additional open-ended question about other environmental exposures within 6 months before illness onset relating to other possible triggers of disease and to specify these and when they occurred. Stressful life events were categorized as major vs minor and as One hundred and twenty-one patients were tested by IP immunoblotting. a Other myositis autoantibodies, which were not examined in the environmental exposure analysis, included: anti-Ro (n = 15), anti-PM/Scl (n = 5), anti-Sm (n = 3), anti-La (n = 2), anti-U5 RNP (n = 1), anti-U3 RNP (n = 1), anti-Ku (n = 1) and anti-Th (n = 1). Some patients have more than one myositis autoantibody. One hundred and one patients were not tested for myositis autoantibodies.