Two cases of neurological manifestations in eosinophilia: variations of one disease?

The hypereosinophilic syndrome is characterized by a long-lasting increase in circulating eosinophils in the absence of a definable etiology and by manifestations of multisystem involvement. It must be differentiated from the eosinophilia-myalgia syndrome related to the ingestion of L-tryptophan, although the clinical features may be similar. Two patients with hypereosinophilia not related to L-tryptophan intake are described who both became clinically symptomatic with neurological manifestations of acute and subacute onset: one with eosinophilic fasciitis and the other with painful polyneuropathy. Both responded well to corticosteroids.