The Diagnosis of Non-Allergic Rhinitis.

Diagnosis of nonallergic rhinitis (NAR) is made after excluding other etiologies of rhinitis symptoms, such as allergic rhinitis or local allergic rhinitis (LAR). A thorough clinical history, examination and negative allergy tests-skin prick test or specific IgE-are essential. Special focus should go to symptom patterns, triggers, and comorbidities. Additional diagnostic tools include nasal allergen provocation tests for LAR, cold dry air provocation for idiopathic rhinitis, and nasal cytology to identify inflammatory cell patterns and NAR with eosinophilia syndrome. Accurate diagnosis is crucial to distinguish NAR subtypes and ensure appropriate management strategies.