Parasitic-induced Loeffler's syndrome: A systematic review based on clinical reports

Loeffler's syndrome, an uncommon pulmonary disorder characterized by transient lung infiltrates and peripheral eosinophilia, is often misdiagnosed as pneumonia. Commonly associated with parasitic infections such as Ascaris lumbricoides and Strongyloides stercoralis, this syndrome remains underdiagnosed owing to clinical overlap with other eosinophilic lung diseases. We aimed to analyze clinical features, diagnostic methods, treatment strategies, and geographical distribution in 23 studies (2014-2024). Higher incidences were observed in developing countries with significant helminth burden, while travel-related cases occur globally. Common symptoms include cough, dyspnea, wheezing, hemoptysis, and pulmonary eosinophilia. Diagnosis involves eosinophil counts, serum IgE, chest imaging, stool microscopy, and bronchoalveolar lavage findings. Children typically exhibit respiratory symptoms and systemic involvement, whereas adults may present with pruritic skin lesions, hypoxemia, right heart strain, or respiratory failure. Treatment centers on antiparasitic and corticosteroid drugs, and supportive care. Increased clinician awareness is essential for early recognition and targeted management, particularly in endemic areas.