A Case of Paragonimiasis Westermani with Pleural Effusion Eight Months after Migrating Subcutaneous Induration of the Abdominal Wall

Abstract

Patients with Paragonimiasis westermani show a typical ring form or nodular shadow on chest X-ray, cough, sputum, and hemosputum. Recently, case reports of Paragonimiasis westermani, acompanied by pneumothorax and pleural effusion, as for Paragonimiasis miyazakii, have been increasing. Paragonimus westermani often causes an ectopic infection in various organs such as the peritoneal cavity, pleural cavity, pericardium, liver, adrenal gland and brain. Cutaneous paragonimiasis is considered one of the typical forms of ectopic infection in its earlier phase, but a few unexpected cases of cutaneous Paragonimiasis westermani have also been reported.
A 68-year old man, who had never eaten fresh-water crab or raw sliced meat of wild boar, noticed subcutaneous induration of the abdominal wall. The induration had been gradually moving upwards and to the right from the infraumbilical region for over 20 days, and then disappeared at the right upper lateral abdominal wall. Eight months later, he developed severe pain in the right lower chest, and a chest X-ray showed right pleural effusion. Laboratory examinations revealed eosinophilia (WBC 3940/mm³, eosinophil 9%), elevated ESR, and an elevated serum total IgE level (5517IU/ml). Ouchterlony's double diffusion test performed with the patient's serum in agarose showed strong bands toward Paragonimus westermani antigen, compared to Paragonimus miyazakii antigen. Immunoelectrophoresis with the patient's serum showed specific bands toward Paragonimus westermani antigen.
This patient was finally diagnosed as having Paragonimiasis westermani infection, and he responded to praziquantel administration. The clinical course of this patient appears to be rare in cases of Paragonimiasis westermani infection. The clinical course of this case resembled some cases of Paragonimiasis miyazakii infection. The present case serves to clarify the migration route of the larvae of Paragonimus westermani in humans.