Frequency of Eosinophilia in Patients Presenting with Bronchial Asthma Presenting at Tertiary Care Hospital

Background: Bronchial asthma is a chronic inflammatory disorder of the airways, characterized by recurrent episodes of airflow obstruction, bronchial hyperresponsiveness, and symptoms such as wheezing, cough, chest tightness, and shortness of breath. Eosinophilia, an elevated count of eosinophilic granulocytes in peripheral blood, reflects ongoing immunoinflammatory activity and serves as a biomarker for disease severity and therapeutic guidance. Objective: To determine the frequency of eosinophilia in patients presenting with bronchial asthma presenting at tertiary care hospital. Study Design: Descriptive cross-sectional study. Duration and Place of Study: The study was conducted from 23 March 2025 to 23 June 2025 at the Department of Pulmonology, Saidu Group of Teaching Hospitals, Swat. Methodology: A total of 143 patients aged 18–70 years, diagnosed with bronchial asthma based on characteristic symptoms and spirometry criteria, were enrolled using non-probability consecutive sampling. Patients with allergic bronchopulmonary aspergillosis, chronic obstructive pulmonary disease, or systemic corticosteroid therapy were excluded. Venous blood samples were collected to measure absolute eosinophil counts, with eosinophilia defined as greater than 500 cells per microliter. Demographic information and comorbidities were recorded. Results: The mean age was 42.44 ± 11.63 years, with 42% males and 58% females. Eosinophilia was present in 44.8% of patients. Younger age, rural residence, and smoking were significantly associated with elevated eosinophil counts. Comorbidities such as diabetes and hypertension showed no significant association. Conclusion: Eosinophilia is a common inflammatory marker in nearly half of patients with bronchial asthma, with age, environmental exposure, and smoking status being important determinants.