The role of nasal cytology in the diagnosis of allergic and non-allergic rhinitis in adult and children.

Chronic rhinitis is a common disease with an incidence of 40% in the Western population. Allergic rhinitis (AR) affects half of the adult population, while in children prevalence of AR vs. non-allergic rhinitis (NAR) of 3-4:1 is reported. Nasal cytology is the diagnostic test that has made it possible to clarify the cellular population of the nasal mucosa. The aims of the present study were to define the distribution of chronic rhinopathy in adult and pediatric populations, to classify "cellular" NAR into subgroups based on cytological features, and to identify overlapped rhinitis (OR). A retrospective study was conducted on 907 patients, divided into two groups: 135 children (69 females and 66 males, average age 9.8 years (range 4-17) and 772 adults (392 females and 380 males, average age 45.28 years (range 18-90). All patients with a suspicion of rhinopathy were submitted to nasal endoscopy, Skin Prick test (SPT), dosage of serum specific IgE, CT scan of nasal, and sinusal structures when chronic rhinosinusitis was suspected. In the adult population of the study, 61% presented a diagnosis of chronic rhinitis: 213 patients (45.2%) had AR, 31 (6.6%) OR, and 227 (48.2%) NAR (77.5% of these patients presented a pattern of "cellular" NAR). In the pediatric population, 83% patients presented a rhinopathy: 61 (54.5%) with AR, 38 (34%) with NAR, and 13 (11.5%) with OR. Within the NAR group, 71% had a "cellular" pattern. Nasal cytology is a tool that provides a more precise differential diagnosis of chronic rhinitis through the study the of nasal mucosa and the identification of "cellular" NAR and OR, even in the pediatric population.