CONTINUING OCCURRENCE OF EOSINOPHILIA-MYALGIA-SYNDROME IN CANADA

Eosinophilia myalgia syndrome (EMS), was defined by the Centers for Di sease Control (CDC) as eosinophilia > 1000 mm(3) and incapacitating my algia without infection or neoplasm. Studies suggested that use of L-t ryptophan (L-T), was a risk factor. We conducted a pharmacoepidemiolog ical survey in Canada where access to L-T is limited. Using the active surveillance method, a 100% sample of potentially involved specialist s and a 15% sample of family physicians from Ontario and Quebec were s urveyed regarding treatment of patients with severe myalgia within the past year. Follow-up amplified clinical and laboratory information. O verall response rates were 61.4%. Thirty-eight per cent of respondents reported at least one patient. Of 6423 patients assessed, 19 'definit e' and 25 'possible' EMS cases were identified. Information from physi cians did not suggest use of L-T in patients with definite or possible EMS. It was considered that the cases found an underestimate of the i ncidence of EMS. Its continuing occurrence in Canada brings causal int erepretations of earlier studies into question.