Clinical, radiological, and laboratory assessment of pulmonary eosinophilia syndrome: a case control study in Saudi Arabia.

BACKGROUND: Pulmonary eosinophilic syndromes (PES) are a heterogeneous group of respiratory disorders characterized by eosinophilic infiltration of lung tissues and/or elevated eosinophil counts in peripheral blood. Accurate diagnosis and understanding of PES are crucial for effective management, especially in underrepresented regions such as Saudi Arabia. OBJECTIVES: To evaluate the clinical, radiological, and biomarker profiles of PES in a Saudi Arabian cohort and to identify factors associated with disease presentation and severity. METHODS: This retrospective case-control study included 95 patients diagnosed with PES at Mouwasat Hospital, Jubail, Eastern Province, Saudi Arabia, from January 2023 to January 2024. Clinical data, laboratory findings (including eosinophil counts, IgE, and FeNO levels), pulmonary function tests, and radiological imaging were analyzed. Statistical analysis was performed using SPSS, with descriptive and inferential methods to assess associations. RESULTS: The cohort had a mean age of 40.5 ± 12.9 years, with a majority being male (65.3%) and Saudi nationals (87%). Elevated eosinophil counts and FeNO levels were significantly associated with PES (p < 0.05). Patients exhibited characteristic radiological patterns such as ground-glass opacities and consolidations. Pulmonary function tests showed reduced FEV₁ and small airway impairment in cases versus controls (p = 0.027). The study observed strong correlations between eosinophilia, airway obstruction, and higher BMI. Smoking was associated with increased symptom severity. CONCLUSIONS: The study underscores the distinct clinical, radiological, and biomarker features of PES in the included population. Integrating multi-modal assessments can improve diagnostic accuracy. These findings emphasize the importance of standardized pathways for PES diagnosis, especially in regions with potential underdiagnosis, and highlight the need for increased awareness among healthcare professionals.