Eosinophils are the principal effector cells involved in the pathogenesis of allergic rhinitis. Cell numbers increase in non-allergic rhinitis patients with eosinophilia, aspirin hypersensitivity and nasal polyposis, as well as in allergic rhinitis patients. Exfoliative nasal cytology can be used in the differential diagnosis of allergic rhinitis.
To evaluate nasal eosinophilia in nasal smears of patients with mild, persistent and intermittent allergic rhinitis.
The study comprised 60 patients with allergic rhinitis and 20 healthy volunteers. The patients were divided into intermittent and persistent allergic rhinitis groups. Nasal smear status, eosinophil numbers and Total Nasal Symptom Scores were compared.
Nasal smear results were pathological in 40 of 60 allergic rhinitis patients, which was significantly higher than the rate in controls. The mean nasal eosinophilia score was significantly higher in the intermittent allergic rhinitis than in the persistent allergic rhinitis group (p = 0.029). There was a positive correlation between nasal eosinophilia score and Total Nasal Symptom Score (r = 0.652; p < 0.05) in persistent allergic rhinitis and intermittent allergic rhinitis patients.
The nasal smear test is inexpensive, objective and simple to perform, and should be part of the diagnostic investigation.