A case of lung paragonimiasis superinfection with hookworm presenting difficulty in discrimination

: A 40-year-old woman, who was born in Thailand and moved to Japan 20 years previously, was admitted to our university hospital because of eosinophilia and abnormal chest radiography findings over a 6-month period. The chest CT showed multiple cavitary nodules in the subpleural area and a tubular structure that extended from each cavity to the pleura. Immunological examination revealed an elevation of antibody titers against Ancylostoma duodenale, Paragonimiasis miyazakii and Paragonimiasis westermanii based on an ELISA assay. In addition, hookworm eggs were found in the stool. We firstly administered pyrantel pamoates, following which the eggs become undetectable. Nevertheless, eosinophilia and abnormal chest CT findings persisted. We diagnosed the patient as having a superinfection with paragonimiasis and hookworm, then administered praziquantel. Subsequently, the number of eosinophils returned to a normal level and the abnormal shadow in the chest CT images diminished without scarring. The final diagnosis was a superinfection of paragonimiasis and hookworm.