Eosinophilia-myalgia syndrome, toxic-oil syndrome, and diffuse fasciitis with eosinophilia.

Eosinophilia-myalgia syndrome reached epidemic proportions in 1989. Its precise etiology remains uncertain, yet virtually all cases were associated with the ingestion of L-tryptophan containing trace amounts of several chemicals. Clinical and pathologic features of eosinophilia-myalgia syndrome are similar to those of the toxic-oil syndrome, which occurred in Spain in 1981 in association with the ingestion of adulterated rapeseed oil. During the past year, the epidemiology of eosinophilia-myalgia syndrome has been better defined, with a second trace contaminant linked to this condition. Knowledge of the clinical and histopathologic features of eosinophilia-myalgia syndrome has also expanded. These and other important advances in the understanding of eosinophilia-myalgia syndrome, toxic-oil syndrome, and diffuse fasciitis with eosinophilia are presented.