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

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.

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.

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.

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).

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.

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.