This study is designed to learn more about EMS that develops in patients taking L-5-hydroxytryptophan. The study is open to patients newly diagnosed with eosinophilia myalgia who have taken L-5-HTP. Patients in the study will have a physical examination and urine and blood tests. They may also have X rays, an electrocardiogram, magnetic resonance imaging (MRI), and a skin test for tuberculosis. They will have a psychiatric interview, take a memory test, and fill out questionnaires relating to sadness and depression.