EOSINOPHILIA-MYALGIA-SYNDROME AMONG THE NON-L-TRYPTOPHAN USERS AND PRE-EPIDEMIC CASES

Objective. Eosinophilia-myalgia syndrome (EMS) has been associated wit h L-tryptophan (LT) use since 1989, but as yet no etiologic agent has been identified. We describe the non-L-tryptophan associated cases of EMS, and those patients with illness onset preceding the 1989 epidemic . Methods. Review of all patients in the EMS national state based surv eillance system administered by the Centers for Disease Control and Pr evention (CDC) who satisfied the EMS surveillance case definition. Res ults. Of 1345 persons with EMS that satisfied the CDC surveillance cas e definition for EMS, 26 (2%) persons reported not having used LT (non -LT). Persons who did not use LT were significantly younger (mean age 39 years; p=0.02) and were more likely than LT users to have onset of their illness before the EMS epidemic (before July 1, 1989) (p <0.001) . Non-LT users reported fewer pulmonary symptoms but had rates of neur opathy and scleroderma-like skin changes similar to LT users. Non-LT u sers had lower mean eosinophil counts (5.6x10(9) cells/l; LT users 6.2 x10(9) cells/l), reported no EMS attributable deaths, but were hospita lized (48%) more often than LT users (34%). Of the 1345 EMS cases, 191 (14%) reported a pre-epidemic illness onset. Symptoms of peripheral e dema, rash, scleroderma-like skin change, alopecia, and neuropathy wer e more prevalent in pre-epidemic patients. Mean eosinophil count was s ignificantly higher for epidemic patients than for pre-epidemic patien ts (p=0.004). Conclusion. Non-LT EMS cases were more likely to be youn ger and to have a pre-epidemic illness onset of EMS, but otherwise wer e similar to LT associated EMS cases. Pre-epidemic EMS cases were more likely to report the presence of neuropathy and scleroderma-like skin change, but not pulmonary symptoms, hospitalization, or death.