Nonallergic rhinitis Pathophysiology and models for study

Abstract

Nonallergic rhinitis is a diagnosis of exclusion which is given to patients who suffer perennial nasal congestion, rhinorrhea, and/or sneezing with no identifiable allergic etiology. Because there is still no clear understanding of the pathophysiology, it is possible that a number of different disease processes may be included within this clinically defined entity. This report does not attempt to present an overall discussion of the clinical approaches to patients with nonallergic rhinitis. Instead, an outline is presented of various research approaches which may be used in its study. A number of nasal provocation models using nonallergic stimuli are available for application in the laboratory. These include intranasal methacholine challenges, intranasal histamine challenges, nasal inhalation of cold dry air, and intranasal capsaicin challenges. These models provide certain insights into mechanisms of nonallergic hyper-responsiveness. An additional approach to the study of nonallergic rhinitis is to examine available therapies, allowing the clinician to evaluate various pathways of importance in the disease process. These approaches provide a certain understanding of this common but perplexing entity, although further study is still required.

Factors affecting pain intensity in a pain model based upon tonic intranasal stimulation in humans

“…While this technique has been employed by others to induce experimental non-allergic rhinitis in humans [22], our present and previous work [11,12] demonstrates its suitability for the assessment of pain and analgesia. The painful stimulation does not lead to lasting damage; it has been shown that it can be applied repeatedly.…”

Immunolocalization of inducible nitric oxide synthase and 3-nitrotyrosine in the nasal mucosa of patients with rhinitis

“…Allergic rhinitis is an immunoglobulin (Ig) E-mediated hypersensitivity of the nasal mucosa. In contrast, nonallergic rhinitis is a diagnosis of exclusion, with patients having symptoms of perennial rhinitis and no identifiable allergic cause [18]. In both forms of rhinitis, inflammatory cells are present in the late or chronic phase of affected tissues and may have an important pathological role.…”

Vasomotor Rhinitis

“…Patients with chronic vasomotor rhinitis generally are less responsive to pharmacologic therapy than those with allergic rhinitis [46][47][48]. Two medications (eg, intranasal steroids and the topical antihistamine azelastine) have been useful in treating the total symptom complex of chronic nonallergic rhinitis.…”