The changes in the nasal secretions of eosinophils during the immediate nasal response to allergen challenge.

In 162 patients with allergic rhinitis due to immediate hypersensitivity, nasal provocation tests (NPT) were supplemented by recording of the eosinophils in the nasal secretions (NS). Nasal secretion specimens were obtained before and repeatedly after allergen challenge and stained by a modified Hansel's method. The 188 positive immediate nasal responses (INR) that correlated with positive skin tests and history and 92 negative INR that correlated with negative skin tests and history were studied. Several different types of eosinophil response to allergen challenge were observed. Eosinophilia was found in the NS in 84% of patients with positive INR but in only 49% of patients with negative INR. The eosinophil count before allergen challenge was low in 79.5% of positive INR and in 76.5% of negative INR, whereas it was high in 20.5% of positive INR and in 23.5% of negative INR. The positive INR were accompanied by significant changes (p less than 0.01) in the eosinophil count between before and after allergen challenge in 74% and the negative INR in only 19% of the cases. These changes appeared within 30 min after allergen challenge. This study shows that only a single count of eosinophils in the NS is not a suitable indicator of nasal allergy. The recording of eosinophils in the NS can be considered as a useful supplementary diagnostic parameter for the possible involvement of immediate hypersensitivity in the nasal mucosa if (1) the eosinophil count is related to a certain allergen and (2) the eosinophils are recorded before and repeatedly up to 60 min after allergen challenge.