L-tryptophan-associated eosinophilic perimyositis, neuritis, and fasciitis. A clinicopathologic and laboratory study of 25 patients.

We have described the spectrum and prevalence of the clinical and laboratory manifestations of a multisystem disorder associated with the ingestion of L-tryptophan. At least 3 subsets of clinical disease have been identified: 1) a neuromuscular disorder which may present with myalgias and mild weakness and then progress to quadriparesis related to an axonal neuropathy and interstitial myositis (perimyositis), 2) a syndrome of eosinophilic fasciitis with characteristic cutaneous induration, and 3) the Löffler syndrome consisting of pulmonary infiltrates with eosinophilia. Corticosteroids may be useful for patients with the Löffler syndrome and offer only a modest benefit in the majority of patients with neuromuscular disease. The clinical course appears to be chronic, and the long-term sequelae of this disorder are unknown. The etiologic agent remains undetermined; however, studies are in progress to examine the mechanism of eosinophilia, appropriate therapeutic intervention, and the long-term outcome of the affected individuals.