Clinical, Laboratory and Radiological Features of Paragonimiasis Misdiagnosed as Pulmonary Tuberculosis

Paragonimiasis presents with nonspecific symptoms and radiologic findings, allowing for the possibility of misdiagnosis. Diagnosis is generally delayed due to lack of suspicion and presentation similar to pulmonary tuberculosis.

A prospective observational study was carried out on 20 subjects at Civil Service Hospital of Nepal from March 2015 to June 2019 who presented with eosinophilia and pulmonary symptoms, and were treated empirically with Anti-tubercular therapy for suspicion of pulmonary tuberculosis.

The median age of the patient was 34 years. Mean blood absolute eosinophil count was 16678/ul. Fever was present in 80% (n=16). Cough was present in 90% (n=18). Pleural effusion was noticed in 100% (n=20). Chest computed tomography showed ground-glass opacities in 65% (n=13) of patients. Pleural fluid eosinophilia (>10%) was evident in all patients. Pleural fluid LDH was elevated in 85% (n=17) of patients. Similarly, ADA was high (>40U) in 75% (n= 15) of patients, and pleural fluid sugar was low in 80% (n=16) of patients. All patients (100%) gave a history of crab or snail consumption. Paragonimus egg was detected in five (25%) patients. Twenty patients fulfilled definite or probable diagnostic criteria of paragonimiasis. Ninety-five (n=19) patients responded to praziquantel.

Unavailability of serologic tests or failure to demonstrate parasitic egg under the microscope should not discourage physicians to consider the diagnosis of paragonimiasis when marked eosinophilia, high LDH levels, and low glucose levels are identified in pleural fluid of a patient with a history of raw crab or snail consumption.