Objective assessments of allergic and nonallergic rhinitis in young children.

Background: Allergic and nonallergic rhinitis are common childhood disorders.
Objective: To study nasal eosinophilia and nasal airway patency in young children with allergic and nonallergic rhinitis to assess the pathology behind such diagnoses.
Methods: We investigated 255 children at six years of age from the Copenhagen Prospective Study on Asthma in Childhood birth cohort assessing rhinitis history, specific immunoglobulin E relevant to rhinitis symptoms, nasal eosinophilia and nasal airway patency by acoustic rhinometry before and after decongestion. Associations were studied in a multivariate graphical model corrected for gender, height and nasal steroid usage.
Results: Allergic rhinitis was significantly and directly associated with irreversible nasal airway obstruction (reduced decongested nasal airway patency) (P = 0.004), whereas nonallergic rhinitis was not. Both allergic rhinitis (P = 0.000) and nonallergic rhinitis (P = 0.014) were directly and significantly associated with nasal eosinophilia, but this association was stronger for allergic rhinitis.
Conclusion: Allergic rhinitis and nonallergic rhinitis are of different pathologies as suggested from their different associations not only to allergy but importantly also to irreversible nasal airway obstruction and eosinophilic inflammation. Allergic rhinitis was significantly associated with nasal eosinophilia and irreversible nasal airway obstruction suggesting chronic inflammation and structural remodeling of the nasal mucosa in children at the age of 6 years. Nonallergic rhinitis exhibited no change in the nasal airway patency, but some nasal mucosal eosinophilia albeit less than children with allergic rhinitis.