THE NATURAL-HISTORY OF EOSINOPHILIA-MYALGIA-SYNDROME IN A TRYPTOPHAN-EXPOSED COHORT IN SOUTH-CAROLINA

Background: In a previous study, we did follow-up on 418 patients who were exposed to tryptophan in 1989, of whom 47 (11%) had definite and 63 (9%) possible eosinophilia-myalgia syndrome (EMS). Methods: We asse ssed mortality and clinical spectrum of illness since 1989 for 242 (58 %) of the 418 tryptophan-exposed patients from the original study. To assess outcomes, we used hospital and death records, interviewer-admin istered questionnaires, physical examinations, and laboratory tests. R esults: During the follow-up interval, mortality from all causes was 1 9% in those with definite EMS, 7% in possible EMS, and 3% in those who were not ill. The age- and sex-adjusted mortality in those with defin ite EMS was more than 3 times that of the general population or of try ptophan users in the practice who were not ill. Six deaths (66%) among the definite EMS case patients occurred during the 18 months immediat ely after symptom onset. Compared with the tryptophan users who were n ot ill, survivors with definite EMS continued to report excess morbidi ty for 6 major EMS symptoms (myalgia, arthralgia, weakness, rash, alop ecia, and sclerodermiform skin changes), but they also reported that t he symptom number and severity diminished with time. None of the trypt ophan users who were not ill in 1989 developed a symptom complex sugge sting new EMS during the follow-up interval. Conclusions: This study a ssessing a tryptophan-exposed population found those persons who devel oped EMS during the 1989 epidemic were at increased risk for death, pa rticularly early after disease onset. Survivors reported improvement o r resolution of major symptoms, suggesting that the severity of EMS di minishes with time. We found no evidence of delayed onset of EMS in tr yptophan users who were not ill in 1989, regardless of the brand used.