Peripheral Eosinophilia and Clinico-radiological Characteristics among Health Screening Program Recipients

BACKGROUND Eosinophilia is well recognized in specific conditions. The objective of the present study was to determine clinico-radiologic characteristics of eosinophilia and changes in prevalence over 10 years in recipients of private health screening program at a tertiary hospital in Korea. METHODS Data of private health screening program recipients at the health promotion center of Chung-Ang University Hospital from 2004 to 2013 were collected. Health-related questionnaires and laboratory findings of private health screening program with possible relation with eosinophilia were reviewed. Results of enzyme-linked immunosorbent assay (ELISA) for parasite, chest computed tomography, and pulmonary function test were also reviewed. RESULTS The cumulative prevalence of eosinophilia was 4.0% (1,963 of 48,928). Prevalence of eosinophilia showed a decreased trend from 2004 to 2013. Most cases (96.6%) had mild degree of eosinophilia. Eosinophilic subjects were older and male-predominant. They showed lower levels of forced expiratory volume in 1 second (FEV₁%), forced vital capacity (FVC%), and FEV₁/FVC than those without eosinophilia. Eosinophilic subjects showed higher positive rate for common parasite in ELISA than those without eosinophilia. On radiologic findings, consolidation and ground glass opacities were positively associated with the degree of eosinophilia. When eosinophil was classified based on severity, statistically significant correlation between the severity of eosinophil and radiologic abnormalities was found. CONCLUSION Eosinophilia is uncommon in healthy population. It usually occurs at a mild degree. Eosinophilic patients have more radiologic abnormalities compared to those without eosinophilia. Such radiologic abnormalities are associated with the severity of eosinophilia.