A modern-day medical mystery known as the eosinophilia-myalgia syndrome (EMS), an illness that reached epidemic proportions in the United States in late 1989, is evolving rapidly. Much progress has been made already in terms of the recognition of the syndrome,1,2 its association with ingestion of the essential amino acid L-tryptophan,3 the detection of contaminants arising as a result of changes made in the manufacturing process,4 and the definition of the clinical spectrum of the syndrome.2,5-7 Credit is due the many practitioners, epidemiologists, toxicologists, and clinical investigators who have brought us to the present level of understanding. But, many questions remain unanswered and much research is needed to understand this illness fully. Answers to such questions will not only improve our understanding of EMS, but will almost certainly improve our understanding of other fibrotic cutaneous disorders.
L-Tryptophan is the scarcest of the amino acids, and vertebrates depend on exogenous sources of this
Silver RM. Unraveling the Eosinophilia-Myalgia Syndrome. Arch Dermatol. 1991;127(8):1214-1216. doi:10.1001/archderm.1991.01680070114018