The recent delineation of a clinical syndrome marked by
eosinophilia,
myalgia, and scleroderma-like skin changes associated with
L-tryptophan use has necessitated the Centers for Disease Control to initiate a health alert. The likely association of
L-tryptophan ingestion with a syndrome that mimics
eosinophilic fasciitis (Shulman's syndrome) further identifies an environmental agent associated with an inflammatory sclerosing
rheumatic disease process. In this report, we present the clinical, morphologic, and
enzyme histochemical findings in muscle, skin, and fascia biopsies from 14 cases fulfilling the Center for Disease Control diagnostic criteria for
L-tryptophan-associated
eosinophilia-myalgia syndrome. The clinical syndrome reveals a high incidence of
arthralgia, elbow
contracture, and clinical neuropathy. The absence of significant change in
creatine kinase or sedimentation rate allows for diagnostic separation from other
inflammatory myopathies. Histoenzymatic features in muscle biopsies reveal a preferential epimysial-perimysial noneosinophilic infiltration characterized by
acid phosphatase reactive
histiocytosis, nonnecrotizing venulitis, perineural
inflammation within dermis and perimysium, type II fiber
atrophy with superimposed
denervation features, and perifascicular
alkaline phosphatase reactivity representing early neofibroplasia. The constellation of changes in skin, fascia, and muscle, with the defined clinical syndrome, allows for accurate differentiation from allied syndromes, including eosinophilic
polymyositis, scleroderma,
idiopathic polymyositis/
dermatomyositis,
polyarteritis nodosa, and toxic oil syndrome. Accurate differentiation from
eosinophilic fasciitis still rests on a history of
L-tryptophan ingestion.