Eosinophilia-myalgia syndrome

Eosinophilia and myalgia rarely coexist, except in cases of trichinosis, eosinophilic fasciitis, eosinophilic myositis, Churg-Strauss syndrome, hypereosinophilic syndrome and toxic oil syndrome. Recently, a syndrome of eosinophilia and severe myalgia has been associated with the consumption Of L-tryptophan. Martin and associates describe the clinical spectrum of eosinophilia-myalgia syndrome in 20 patients.

In all except one case, the patients met the Centers for Disease Control case definition of eosinophilia-myalgia syndrome (peripheral blood eosinophil count greater than 1,000 per mm[.sup.3] [1.0 X 10[.sup.9] per L), severe generalized myalgia and absence of other recognized causes).

Three of the patients developed eosinophilic fasciitis. Pneumonitis and myocarditis developed in one patient, neuropathy culminating in respiratory failure occurred in one, encephalopathy in one and fibrosis around the common bile duct in one patient. No association was apparent between the dosage of L-tryptophan or the duration of exposure and the syndrome. No organic contaminants could be identified in the preparations of L-tryptophan that were taken by the patients.

Biopsy specimens from 12 patients showed a mononuclear exudate with a variable number of eosinophils in affected tissues. Immunofluorescence showed major basic protein outside the eosinophils in affected tissues, indicating that toxic granule proteins were released in diseased organs.

L-Tryptophan was discontinued by all of the patients. Corticosteroids were prescribed for 16 of the patients. One patient received diuretics only. No drug therapy was prescribed for three patients. Four patients have recovered fully, while the others remain stable or are slowly recovering. One patient is gravely ill.

Although the pathologic alterations that occur in eosinophilia-myalgia syndrome are distinctive, the authors note that none are unique. Further study of this condition is warranted. (Annals of Internal Medicine, July 15, 1990, vol. 113, p. 124.)

COPYRIGHT 1990 American Academy of Family Physicians
COPYRIGHT 2004 Gale Group