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Paper text:
a 34-year - old woman visited the emergency room for dyspnea and chest pain , which had developed two weeks earlier . on the chest x - ray
, a moderate amount of pneumothorax with multifocal air - fluid levels was found on the left side . in the peripheral blood test ,
the white blood cell count was within the normal range with 9,90010 cells/l , but the eosinophil count was elevated by 2.110 cells/l ( 21.1% ) .
she had returned from a trip to japan 15 days earlier , where she had eaten sliced raw fish and raw crab .
chest computed tomography ( ct ) scan revealed the presence of subpleural bullae and sub - lobular consolidation accompanied with peripheral ground glass attenuations in the lung parenchyma ( fig .
1 ) along with a moderate amount of hydropneumothorax on the left side , a small amount of effusion on the right side , and several abscess pockets in the liver , because of which pulmonary paragonimiasis was suspected . a 20-fr suture rib trocar catheter ( argyle ;
the serum and the pleural fluid were positive for paragonimiasis westermani by a parasite - specific antibody immunoglobulin g ( igg ) enzyme - linked immunosorbent assay ( elisa ) test . under the diagnosis of paragonimiasis , the patient was medicated with a 3-day course of praziquantel ( distocid 600 mg ) 80 mg / kg divided into 3 doses ; she was discharged on the 8th day .
four months later , follow - up chest ct scan revealed that the lesions in the lung and liver were resolved , and the eosinophil count in the peripheral blood was normalized .
a 21-year - old male soldier visited the outpatient clinic for dyspnea followed by acute chest pain .
chest x - ray revealed a moderate amount of pneumothorax on the right side , which was the second event of pneumothorax after repeated thoracoscopic surgery performed 4 years and 3 months earlier . on the left side ,
a small amount of pneumothorax was also detected and the patient had undergone thoracoscopic surgery 10 months previously .
a 7-fr two - lumen central venous catheter ( arrow international inc . , reading , pa , usa ) was inserted into the right pleural cavity and conventional thoracotomy with chemical pleurodesis was planned . in the high - resolution ct , subpleural nodules and ground glass attenuations in both lungs
2 ) . the patchy ground glass attenuation increased in extent as compared to 4 months earlier .
radiologically , pulmonary paragonimiasis was suspected , but laboratory studies did not show any abnormal findings in the peripheral blood and the parasite - specific antibody igg was negative in the serum .
the patient had eaten crabs preserved in soy sauce a month earlier , but he insisted that they were sea crabs .
however , he had drunk stream water frequently during outdoor military drills . under the diagnosis of paragonimiasis ,
he was treated with a 3-day course of praziquantel ( cisticid 600 mg ) 80 mg / kg divided into 3 doses .
the pathologic samples obtained through previous operations were reviewed again , but there were no abnormal findings except the presence of bullae .
two months later , he underwent a chest ct scan ; the results revealed that the bilateral pneumothorax was resolved and previously noted patchy ground glass attenuations , subpleural nodules , and cavitary nodules in both the upper lobes were improved with small residual opacity .
a 34-year - old woman visited the emergency room for dyspnea and chest pain , which had developed two weeks earlier . on the chest x - ray
, a moderate amount of pneumothorax with multifocal air - fluid levels was found on the left side . in the peripheral blood test ,
the white blood cell count was within the normal range with 9,90010 cells/l , but the eosinophil count was elevated by 2.110 cells/l ( 21.1% ) .
she had returned from a trip to japan 15 days earlier , where she had eaten sliced raw fish and raw crab .
chest computed tomography ( ct ) scan revealed the presence of subpleural bullae and sub - lobular consolidation accompanied with peripheral ground glass attenuations in the lung parenchyma ( fig .
1 ) along with a moderate amount of hydropneumothorax on the left side , a small amount of effusion on the right side , and several abscess pockets in the liver , because of which pulmonary paragonimiasis was suspected . a 20-fr suture rib trocar catheter ( argyle ;
the serum and the pleural fluid were positive for paragonimiasis westermani by a parasite - specific antibody immunoglobulin g ( igg ) enzyme - linked immunosorbent assay ( elisa ) test . under the diagnosis of paragonimiasis , the patient was medicated with a 3-day course of praziquantel ( distocid 600 mg ) 80 mg / kg divided into 3 doses ; she was discharged on the 8th day .
four months later , follow - up chest ct scan revealed that the lesions in the lung and liver were resolved , and the eosinophil count in the peripheral blood was normalized .
a 21-year - old male soldier visited the outpatient clinic for dyspnea followed by acute chest pain .
chest x - ray revealed a moderate amount of pneumothorax on the right side , which was the second event of pneumothorax after repeated thoracoscopic surgery performed 4 years and 3 months earlier . on the left side ,
a small amount of pneumothorax was also detected and the patient had undergone thoracoscopic surgery 10 months previously . a 7-fr two - lumen central venous catheter ( arrow international inc . ,
reading , pa , usa ) was inserted into the right pleural cavity and conventional thoracotomy with chemical pleurodesis was planned . in the high - resolution ct , subpleural nodules and ground glass attenuations in both lungs
2 ) . the patchy ground glass attenuation increased in extent as compared to 4 months earlier .
radiologically , pulmonary paragonimiasis was suspected , but laboratory studies did not show any abnormal findings in the peripheral blood and the parasite - specific antibody igg was negative in the serum .
however , the elisa test for paragonimiasis westermani in the pleural fluid was positive . the patient had eaten crabs preserved in soy sauce a month earlier , but he insisted that they were sea crabs .
under the diagnosis of paragonimiasis , he was treated with a 3-day course of praziquantel ( cisticid 600 mg ) 80 mg / kg divided into 3 doses .
the pathologic samples obtained through previous operations were reviewed again , but there were no abnormal findings except the presence of bullae .
two months later , he underwent a chest ct scan ; the results revealed that the bilateral pneumothorax was resolved and previously noted patchy ground glass attenuations , subpleural nodules , and cavitary nodules in both the upper lobes were improved with small residual opacity .
human infections with the paragonimus species have been reported mainly in eastern asia , when they consume living metacercariae in tissues of crayfish or crab , or in the fingers and utensils of the persons preparing the meals .
the incidence of pulmonary paragonimiasis in korea has decreased rapidly since the 1970s due to population reduction of the intermediate hosts through industrialization and changes in dietary habits .
survey data from the 1990s indicated that the prevalence of human paragonimiasis had fallen to approximately 1/100th of that in the early 1970s . nowadays , according to the increasing prevalence of outdoor living and widespread encampment in korea , the risk of parasite infection caused by accidental eating of undercooked freshwater crab or crayfish may be growing .
moreover , classic symptoms such as chronic cough with rusty - brown sputum , hemoptysis , pleurisy , and fever   are common in respiratory disease .
eosinophilia is known as the characteristic feature of parasite infection in 70% to 80% of patients [ 2 - 4 ] , but tomita et al .  
reported that a normal or marginal level of eosinophilia could be observed due to the low intensity of infection or earlier diagnosis . because eosinophile count differs from patient to patient   and according to the main location of lesion , and even disappears in the chronic phase
later , thin - walled cysts , dense mass - like consolidation , nodules , or bronchiectasis may appear .
therefore , paragonimiasis should be included in the differential diagnosis when a pulmonary or pleural lesion is detected in patients who have lived in or traveled to paragonimiasis - endemic areas , such as korea , china , and japan .
moreover , in order to lower the high recurrence rate in secondary pneumothorax , treatment for the underlying pulmonary disease should be accompanied . in these cases ,
the patients were diagnosed by the secondary spontaneous pneumothorax induced by paragonimiasis , but their clinical manifestation was different and they had mixed radiological lesions .
paragonimiasis should always be considered in the list of differential diagnosis , when pneumothorax is developed in patients who have a risk of eating raw fresh - water crab or drink stream water , and it is necessary to perform a chest ct scan and elisa test to confirm the diagnosis .
when the juvenile worms of the genus paragonimus migrate and cause defects on the surface of the visceral pleura , pneumothorax can develop . 
 a 34-year - old woman was admitted for pneumothorax with which was developed after she ate raw fish and crab . a 21-year - old male soldier presented with recurrent bilateral pneumothorax without eosinophilia , caused after drinking stream water frequently . in both patients 
 , paragonimiasis was suspected from the computed tomography scan and confirmed by an enzyme - linked immunosorbent assay test of the pleural fluid . 
 when pneumothorax develops in patients who have ingested raw fresh - water crab or stream water , paragonimiasis should always be considered in the differential diagnosis .