Intestinal strongyloidiasis manifesting as eosinophilic pleural effusion

Strongyloidiasis caused by the helminth Strongyloides stercoralis is usually asymptomatic or causes mild dermatologic or gastrointestinal symptoms. In immunocompromised hosts, hyperinfection and dissemination can occur. In this case, I describe a nonimmunocompromised Southeast Asian man who had an eosinophilic pleural effusion, peripheral eosinophilia, and rhabditiform larvae of S stercoralis in the stools. There was complete resolution of the pleural effusion after thiabendazole therapy, thus suggesting strongyloidiasis as the cause of the effusion. Helminthic infections like strongyloidiasis should be considered in the differential diagnosis of an eosinophilic pleural effusion, especially in individuals from endemic areas.