Nasal cytology in rhinitis children: comparison between brushing and blowing the nose.

Allergic rhinitis is a common disease in childhood, but nasal cytology is rarely used by pediatricians. We compared two techniques of cell sampling, brushing and blowing the nose, among 77 children suffering from chronic rhinitis, of whom 59 were allergic. Staining by the May-Grunwald-Giemsa method enabled the evaluation of the density of cells and especially differential counting of the inflammatory cells. Staining by the Luna method was used as a control for the eosinophils. For the eosinophil count, we found a strong correlation between the two methods of collecting the nasal secretions (r = 0.96). Because blowing the nose is painless and easy to perform, it is more appropriate than brushing in routine use for the diagnosis of allergic rhinitis in children and in nasal challenge with allergens.