Loeffler's Syndrome Induced by the Transmigration of Strongyloides stercoralis to the Lungs: A Case Report and Literature Review.

Loeffler's syndrome is a rare, benign respiratory disease usually associated with peripheral eosinophilia, first described by Wilhelm Loeffler in 1932. It is caused by the larvae of helminths such as hookworms, , and S that transmigrate through the lungs during the active phase of infection. We present a case of a 53-year-old man who complained of a productive cough with intermittent hemoptysis and left-sided posterior chest pain. Initial evaluation revealed ground-glass opacity in the left upper lobe on chest X-ray and computed tomography (CT) scan, with laboratory results suggestive of leukocytosis, eosinophilia, and elevated IgE levels. After ruling out other potential diagnoses, strongyloidiasis was suspected. Serology for was positive, and stool studies confirmed the presence of  larvae. The patient was started on ivermectin and followed up in the outpatient clinic. Repeat chest CT after one month showed resolution of the previously noted left upper lobe infiltrate. This case report aims to describe this rare instance of Loeffler's syndrome and provide an update on the epidemiology, risk factors, and association of strongyloidiasis with other diseases and medications.