A Case of Heavy Paragonimiasis Involving a Multi-Organ Presentation with Hypereosinophilia and Hepatic Migration

Paragonimiasis is a parasitic disease caused by the genus Paragonimus, typically transmitted through the ingestion of raw or undercooked freshwater crabs. Although pulmonary involvement is typical, ectopic migration to subcutaneous or hepatic sites is rare and poses diagnostic challenges. A case of paragonimiasis in a 29-year-old Cambodian woman residing in Japan who presented with painless subcutaneous nodules on the chest and abdomen is reported in the current study. She had consumed raw crab 4 months before presentation. Laboratory findings revealed marked eosinophilia (21,000/µL) and elevated immunoglobulin E (5,049 IU/mL). Computed tomography scans revealed pleural effusion, club-shaped pulmonary consolidation, funicular hypodense lesions in the liver, and subcutaneous lesions. Stool and sputum test results were negative for parasite eggs; however, a microplate ELISA indicated a Paragonimus westermani infection. The patient responded well to 3 consecutive days of praziquantel (75 mg/kg/day) and was discharged a week later. This case highlights the importance of considering paragonimiasis in patients with unexplained subcutaneous nodules and eosinophilia, especially when supported by dietary risk factors.