Persistent eosinophilia in 2 patients with eosinophilia-myalgia syndrome

Eosinophilia myalgia syndrome

The term eosinophilia myalgia syndrome (EMS) was coined in 1989 after a cluster of cases with symptoms of incapacitating myalgias and eosinophilia were reported. This syndrome has been only defined as varying degrees of myalgias and peripheral eosinophilia. Case reports of EMS are protean and do not show a consistent clinical picture, raising the question of whether this reflects a single disorder or is a conflation of various disorders. There have been only two studies evaluating the association of EMS with 1-tryptophan. These two included only 23 patients with EMS. Apart from the obvious statistical fragility inherent in such small studies, each is further weakened by differences in the mechanisms by which patients and controls were selected. Furthermore, the continued reports of EMS after 1-tryptophan was removed from the market raise additional questions about the association. Nonetheless, there has been an inordinate reliance on a history of 1-tryptophan ingestion in making the diagnosis of EMS. When presented case studies, clinicians were much more likely to make the diagnosis of EMS when a history of 1-tryptophan ingestion was included. These observations underscore the need for careful application of well-considered diagnostic criteria to the study of new syndromes and their potential associations.

Clinical features of eosinophilia myalgia syndrome and related disorders

EMS, EF, and TOS are all relatively rare disorders. There are considerable data to suggest that most (if not all) of these cases may be due to toxin exposure, although the precise etiologic agent(s) has yet to be identified. It is likely that the pathogenic mechanisms responsible for disease are similar in these entities, and thus the distinctions between these illnesses may be largely semantic. Rational therapy includes the removal of an inciting agent if identified, and the application of symptom-based treatment based on the organ or tissue involved, and whether there is evidence of active inflammation is present.