Clinical follow-up and immunogenetic studies of 32 patients with eosinophilia-myalgia syndrome.

31 patients with L-tryptophan-associated eosinophilia-myalgia syndrome (EMS) that developed during the United States outbreak in 1989 were followed up prospectively at a university hospital outpatient rheumatology clinic for 16 to 24 months from the onset of their illness. Another patient with EMS associated with L-tryptophan in 1988 was followed up for 30 months. 93% of the 28 survivors from the 1989 cohort continue to have symptoms affecting 1-4 organ systems (median 3) and 3 have died, so the disorder produces considerable morbidity and mortality. The chronic sequelae most often associated with long-term disability are sclerodermatous skin thickening (54%), sensorimotor polyneuropathy (61%), proximal myopathy (36%), and severe episodic myalgias (64%). Thrombocytopenia developed in 1 patient. HLA-class II typing revealed a non-significant trend towards an association with HLA-DR4. Early therapy with corticosteroids did not seem to prevent the development of chronic manifestations.