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Article
July 11, 1990

Eosinophilia-Myalgia Syndrome Associated With Exposure to Tryptophan From a Single Manufacturer

Author Affiliations

From the Division of Field Services, Epidemiology Program Office (Drs Slutsker and Watson), and the Division of Environmental Hazards and Health Effects, Center for Environmental Health and Injury Control (Dr Miller), Centers for Disease Control, Atlanta, Ga; and the Oregon Health Division, Department of Human Resources, Portland (Drs Hoesly, Williams, and Fleming).

From the Division of Field Services, Epidemiology Program Office (Drs Slutsker and Watson), and the Division of Environmental Hazards and Health Effects, Center for Environmental Health and Injury Control (Dr Miller), Centers for Disease Control, Atlanta, Ga; and the Oregon Health Division, Department of Human Resources, Portland (Drs Hoesly, Williams, and Fleming).

JAMA. 1990;264(2):213-217. doi:10.1001/jama.1990.03450020065028
Abstract

Although eosinophilia-myalgia syndrome has been linked to use of tryptophan, it has been unclear whether tryptophan itself or a contaminant causes illness. In Oregon, we compared the brand and source of tryptophan used by 58 patients with eosinophilia-myalgia syndrome with the brand and source of tryptophan used by 30 asymptomatic controls identified through a random telephone survey and 63 asymptomatic controls who contacted the Oregon Health Division voluntarily. Although a single brand/retail lot of tryptophan was statistically associated with the development of eosinophilia-myalgia syndrome, there was no common importer, wholesaler, tablet maker, encapsulator, or distributor. However, 45 (98%) of 46 cases had taken a product made by one manufacturer, compared with three (30%) of 10 telephone survey controls and 15 (48%) of 31 volunteer controls. Retail lots of tryptophan from this manufacturer that were associated with cases were significantly more likely to have been produced from January through June 1989 than lots from this manufacturer that were taken by controls. These findings indicate that the recent epidemic of eosinophilia-myalgia syndrome was caused by a contaminant or an alteration in a subset of tryptophan manufactured by a single company in Japan shortly before the outbreak began.

(JAMA. 1990;264:213-217)

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