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

The similarity of eosinophilia-myalgia syndrome (EMS) and toxic-oil syndrome (TOS) to systemic sclerosis and diffuse fasciitis with eosinophilia (DFE) highlights the potential for environmental agents to induce autoimmune disease. Further, a candidate etiologic agent for EMS, 3-(phenylamino)alanine, is chemically similar to the aniline derivative identified in samples of oil implicated in TOS, 3-(N-phenylamino)-1,2-propanediol, suggesting pathogenic overlap. The late-stage manifestations of EMS and TOS are muscle cramping, arthralgia, severe fatigue, and cognitive impairment. This review focuses on the divergent and parallel findings in EMS, TOS, and DFE. The formation of the Environmentally Associated Connective Tissue Disease Study Group within the American College of Rheumatology will provide a forum for the development of registries to study suspected toxin-induced disorders.