What is Rhinitis?
Rhinitis is a condition characterized by inflammation or dysfunction of the nasal mucosa, presenting with one or more of the following cardinal symptoms: nasal congestion, rhinorrhea (anterior and posterior drainage), sneezing, and nasal itching. 1
Core Definition and Clinical Presentation
Rhinitis represents a pattern of nasal symptoms resulting from nasal inflammation and/or mucosal dysfunction. 2 The condition manifests through:
- Nasal congestion - often the dominant symptom 3
- Rhinorrhea - both anterior (runny nose) and posterior (postnasal drainage) 1
- Sneezing - particularly prominent in allergic forms 1
- Nasal itching - more characteristic of allergic rhinitis 1
Major Classifications
Primary Categories
Rhinitis should be classified by etiology into two broad categories: allergic rhinitis and nonallergic rhinitis. 1 However, this represents a simplified framework, as mixed rhinitis (combined allergic and nonallergic) occurs in approximately 44% to 87% of patients with allergic rhinitis and is actually more common than either pure form. 1
Allergic Rhinitis
Allergic rhinitis results from an IgE-mediated immune response to aeroallergens, involving complex mucosal inflammation driven by inflammatory cells and mediators including cytokines, with sensory nerve activation, plasma leakage, and venous sinusoid congestion. 1 This form affects 30 to 60 million people in the United States annually, including 10% to 30% of adults and up to 40% of children. 1
Allergic rhinitis presents in several temporal patterns: 1
- Seasonal - symptoms during specific pollen seasons
- Perennial - year-round symptoms without seasonal variation
- Perennial with seasonal exacerbations - baseline symptoms that worsen seasonally
- Episodic - sporadic symptoms after specific aeroallergen exposures
Nonallergic Rhinitis
Nonallergic rhinitis encompasses periodic or perennial symptoms not resulting from IgE-dependent mechanisms. 1 Major subtypes include:
- Infectious rhinitis - viral infections account for 98% of acute cases, with symptoms lasting up to 10 days 1
- Vasomotor rhinitis (idiopathic rhinitis) - chronic nasal symptoms without immunologic or infectious origin, typically not associated with nasal eosinophilia 1
- NARES (nonallergic rhinitis with eosinophilia syndrome) - characterized by nasal eosinophils in patients with perennial symptoms and occasionally reduced smell, but lacking positive allergy testing 1
- Hormonal rhinitis - including pregnancy-related rhinitis starting after the second month and resolving within 2 weeks postpartum 1
- Drug-induced rhinitis - caused by ACE inhibitors, phosphodiesterase-5 inhibitors, NSAIDs, or rhinitis medicamentosa from overuse of topical decongestants 1
- Occupational rhinitis - arising from workplace airborne substances 1
- Food and alcohol-induced rhinitis - through vagally mediated mechanisms or nasal vasodilation 1
Clinical Impact
Rhinitis represents a pathologic condition with considerable morbidity and financial burden, causing substantial costs related to treatment and lost workplace productivity. 1 It is a significant cause of lost work and school days. 1 The condition also serves as a risk factor for complications including sinusitis, otitis media, asthma, learning disabilities, behavioral changes, and psychological impairment. 2
Key Distinguishing Features
Symptoms suggesting allergic rhinitis: 1
- Pruritus and sneezing (much more common than in nonallergic forms)
- Seasonal exacerbations
- Earlier age of onset (typically before age 20)
- Associated allergic conjunctivitis symptoms
Symptoms suggesting nonallergic rhinitis: 1
- Isolated postnasal drainage
- Symptoms triggered by strong odors (perfume, tobacco smoke)
- Isolated rhinorrhea with eating (gustatory rhinitis)
- Primarily unilateral symptoms (suggesting structural problems)