the first symptoms of JDM in 33-50% of patients, and respiratory infections accounted for 80% of the infections [17] . The lack of control comparator groups in all of these studies, however, does not enable one to conclude that these exposures differ from a healthy population, nor that they are associated with the onset of illness. While infections, particularly upper respiratory infections, are reported frequently in school age children [32] , a prospective matched cohort of new-onset JDM patients reported a higher frequency of antecedent illness in the JDM patients compared with friend controls from the same geographical region [19] . We identified for the first time that a number of other non-infectious exposures also occurred within 6 months of the first signs of illness, including medications, many of which are potentially myopathic or photosensitizing, immunizations, stressful life events and sun exposure. Pachman et al. [16] noted medication use in >60% of patients, including medications for symptoms of early illness or antibiotics to treat associated infections. A listing of medications taken by patients in the present study and in others includes similar medications (Table 4) , and we noted that many of the medications could be potentially myopathic or phototoxic [26, 27, 29, 30] . Drug-induced myositis has been well described with a number of different medications, including D-penicillamine, lipid-lowering agents, L-tryptophan and IFN-a [33, 34] . Myopathic or phototoxic drugs, however, could lead to the first symptoms of myositis. Other environmental factors reported here, including ultraviolet light exposure, emotional stress and heavy weight lifting, have been reported as possible risk factors for adult DM or PM in case-controlled studies [35] [36] [37] [38] .