Recurrent eosinophilic pleuritis caused by sparganum infection: A case report and review of the literature

Rationale: Sparganosis is an infectious disease caused by a larval tapeworm of the genus Spirometra, which commonly invades subcutaneous tissues. Pulmonary and pleural involvement due to sparganum has been rarely reported previously.

Patient concerns: We herein described a case of recurrent eosinophilic pleuritis in a 24-year-old woman. She was admitted with persistent cough and shortness of breath for more than 1 month. Initial chest computed tomography scan suggested right pleural effusion and diffuse pleural thickening. Slightly elevated eosinophil counts were found in both the peripheral blood and pleural fluid. She underwent right pleurectomy but histological examination failed to obtain an etiological diagnosis. Moreover, eosinophilic pleural effusion re-appeared in the contralateral thoracic cavity one month later. After re-admission, we reviewed her medical history meticulously and found she had a history of ingesting raw snake gallbladders before hospitalization. The final diagnosis was confirmed by the markedly positive reaction against sparganum antigen in both serum and pleural fluid sample.

Diagnosis: Eosinophilic pleuritis caused by sparganum infection.

Interventions: After the diagnosis, the patient was treated with praziquantel at 75 mg/kg/d for 3 days.

Outcomes: Pleural effusion absorbed completely and eosinophil count in peripheral blood returned to normal range. No evidence of recurrent pleural effusion had been observed in over one year of follow-up.

Lessons: Clinicians need to be aware the possibility of sparganum infection in cases of eosinophilic pleuritis. The specific enzyme-linked immunosorbent assay remains a useful method in acquiring a rapid diagnosis, especially when histological examination is unable to detect the larvae in the thoracic cavity.