Evidence-based medicine: what is the evidence?

The cytology of nasal secretions in 20 patients with allergic rhinitis and 15 patients with chronic maxillary sinusitis was investigated with transmission electron microscope to study the ultrastructure of the cluster epithelial cells in nasal secretions of allergic rhinitis. The results showed that the cluster epithelial cells were predominant cellular element in allergic nasal secretions. The number of cluster cells correlated positively with the number of eosinophils and the levels of eosinophilic cationic protein. It is suggested that the exfoliation of cluster nasal epithelial cellular elements may be caused by eosinophic cationic protein with resultant hyperreactivity of nasal mucosa.