Eosinophilia–myalgia syndrome

Eosinophilia–myalgia syndrome (EMS) is an incurable and sometimes fatal flu-like neurological condition linked to the ingestion of the dietary supplement L-tryptophan. The risk of developing EMS increases with larger doses of tryptophan and increasing age. Some research suggests that certain genetic polymorphisms may be related to the development of EMS. The presence of eosinophilia is a core feature of EMS, along with unusually severe myalgia (muscle pain).