Allergic Rhinitis and Ocular Allergy: A Correlative Study of Serum IgE, Tear Histamine, and Peripheral Eosinophils.

Abstract

Background: Ocular allergies (OA) and allergic rhinitis (AR) commonly coexist, exacerbating patient symptoms and lowering quality of life. Dual diagnosis is still neglected despite this overlap.

Objective: Assess peripheral eosinophil counts, tear histamine levels, and serum immunoglobulin E (IgE) in AR patients with and without ocular allergies, and correlate these with the intensity of visual symptoms.

Methods: 200 patients from a tertiary hospital were recruited for this prospective study: 100 with AR alone and 100 with AR+OA. Venous blood was used to measure eosinophils and serum IgE. Schirmer strips were used to measure tear histamine. A visual analogue scale (VAS) was used to score visual symptoms.

Results: Patients with both AR and OA had significantly elevated serum IgE (230 ± 58 IU/mL), tear histamine (15.4 ± 4.2 ng/mL), and eosinophils (7.8 ± 2.1%) compared to AR-only patients (p<0.001). VAS scores were higher in the AR+OA group (7.1 ± 1.6 vs. 1.3 ± 0.6).

Discussion: The findings demonstrate that combined AR and OA represent a more severe allergic phenotype, characterized by heightened systemic and local allergic responses. Elevated tear histamine strongly correlated with symptom severity, supporting its use as a practical, non-invasive marker of ocular involvement. The clear biomarker differences between groups highlight the need for routine ocular evaluation in AR patients to avoid underdiagnosis and to guide targeted therapy.

Conclusion: Serum IgE, tear histamine, and eosinophils are elevated in AR+OA patients and may be used for screening, diagnosis, and monitoring of coexisting ocular allergy.