Eosinophilia-myalgia syndrome linked to tryptophan

Eosinophilia-myalgia syndrome has been linked to ingestion of tryptophan, but the exact cause of this recently recognized syndrome is unclear. As in other reported cases, the disease in the patient described here developed while she was taking tryptophan. Although eosinophilia resolved following glucocorticoid therapy, the disease in this patient continues to progress.