From the Research
Eosinophilia myalgia syndrome (EMS) is a rare, serious multisystem disorder characterized by severe muscle pain and elevated levels of eosinophils in the blood, primarily associated with the ingestion of L-tryptophan dietary supplements. This condition typically presents with intense muscle pain (myalgia), fatigue, skin changes, shortness of breath, and sometimes neurological symptoms, as described in a study published in the Annals of Internal Medicine 1. The condition develops in two phases: an acute phase with fever, muscle pain, and skin rash, followed by a chronic phase involving persistent muscle pain, weakness, and potential organ damage.
Clinical Features and Diagnosis
Key clinical features of EMS include:
- Severe myalgias limiting function
- Fatigue
- Rashes
- Edema and weight gain or loss
- Muscle weakness
- Shortness of breath Laboratory findings often show eosinophilia, normal erythrocyte sedimentation rate, and elevated aldolase with normal or low creatine kinase values, as noted in a study published in The Journal of Rheumatology 2. Biopsy specimens may reveal a mononuclear exudate with a variable admixture of eosinophils in affected tissues.
Treatment and Management
Treatment primarily focuses on symptom management, including corticosteroids like prednisone to reduce inflammation and eosinophil counts. A study published in The Journal of Rheumatology found that seven patients treated with prednisone showed prompt disappearance of eosinophilia, although myalgias and neuropathy persisted 3. Immunosuppressive medications such as methotrexate or cyclosporine may be added for severe cases. Physical therapy helps maintain muscle function, while pain management strategies are important for quality of life.
Cause and Pathophysiology
The exact cause of EMS remains incompletely understood, but it appears to involve an abnormal immune response, possibly triggered by contaminants in certain supplements or medications, as suggested by a study published in Nutrition Reviews 4. A more recent study published in Arthritis and Rheumatism in 2011 provided evidence of activated transforming growth factor β and interleukin-4 signaling in the lesional skin of a patient with L-tryptophan-associated EMS 5.
Long-term Monitoring
Patients diagnosed with EMS require long-term monitoring as the condition can cause lasting health effects. Given the rarity and severity of EMS, it is crucial to approach each case with careful consideration of the most recent and highest quality evidence available, prioritizing morbidity, mortality, and quality of life as outcomes.