Prevalence and management of eosinophilia based on periodic health examinations in primary care clinics.

Background: Eosinophilia is a common, hematologic abnormality detected in periodic health checkups with diverse etiologies. There are a few clinical practice guidelines for the management of eosinophilia. Objectives: To determine the prevalence of eosinophilia among patients undergoing periodic health examinations, evaluate its management and outcomes, and identify its associated factors. Methods: We conducted a retrospective study that included patients with eosinophilia diagnosed during the 2018 periodic health examinations at Songklanagarind Hospital. Results: The prevalence rate of eosinophilia was 9.6% (988/10,299), and most patients (52.6%) were male with a median age of 53.0 (42.0-61.0) years. Only 174 patients (17.6%) were diagnosed and further examined to identify the cause of eosinophilia; including an examination of medical history (18.4%), physical examination (93.1%), laboratory analysis (9.2%), and consultation with internists (14.9%). Empirical anthelmintic therapy was administered in 130 patients (74.7%), and 49.2% achieved resolution. The possible causes of eosinophilia were identified in 20.7% (204/988), the most common cause being atopic disease (51.5%). Patients with moderate-to-severe eosinophilia were significantly more likely to be diagnosed, undergo further laboratory tests, and proceed with consultations with internists (adjusted OR [95% CI] = 3.52 [1.97-6.32], 17.13 [5.74-51.11], and 6.38 [1.95-20.93], respectively). Conclusions: Eosinophilia is commonly identified in periodic health examinations, and most primary physicians lack knowledge regarding the diagnostic work-up required to determine the cause of eosinophilia. Empirical anthelmintic therapy showed satisfactory efficacy for the management of eosinophilia in areas where parasite infection is endemic.