Eosinophilia-Myalgia Syndrome (EMS) is a rare disorder that is characterized by a combination of eosinophilia (an increase in the number of eosinophils, a type of white blood cell) and myalgia (muscle pain). It is believed to be caused by exposure to the toxic amino acid L-tryptophan, which was found in some dietary supplements in the late 1980s.
The dermatologic manifestations of EMS include skin rashes, hives, and itching. These symptoms can be severe and may be accompanied by other symptoms such as fever, joint pain, and fatigue. Treatment typically involves the use of corticosteroids and antihistamines to reduce inflammation and itching. In some cases, immunosuppressants may be used to reduce the severity of the symptoms.