Sparganum-Induced Eosinophilic Pleural Effusion: a Case Report Emphasizing Laboratory Diagnostic Strategies.

Background: Eosinophilic pleural effusion (EPE), characterized by atypical symptoms and rarity, is easily over-looked and misdiagnosed.

Methods: The patient underwent comprehensive routine laboratory tests including blood analysis and pleural effusion examination, along with B-ultrasound and computed tomography (CT) imaging. Based on combined evaluation of the epidemiological history, serum-specific parasite antibody detection and targeted Next-Generation Sequencing were performed on the clinical specimens.

Results: The blood routine and pleural fluid routine of the patients suggested that the eosinophils were significantly increased. The serum-specific parasite antibody detection showed positive sparganosis antibody. Based on the diagnosis of sparganosis for this patient, he was treated with praziquantel and pleural effusion drainage, and the symptoms improved significantly.

Conclusions: The etiological diagnosis of EPE is challenging and requires a comprehensive evaluation of clinical symptoms, epidemiological history, and laboratory test results. When parasitic pleural effusion is strongly suspected, tests such as serum-specific parasite antibody detection can aid in confirming the diagnosis.