Chronic Allergic Rhinitis: Definition, Prevalence, and Symptoms
Definition
Chronic allergic rhinitis is an IgE-mediated inflammatory disorder of the nasal mucosa characterized by symptoms persisting for more than 4 consecutive days per week and more than 4 consecutive weeks per year, triggered by allergen exposure. 1 It occurs when disruption of the epithelial barrier allows allergens to penetrate the nasal mucosal epithelium, inducing a T-helper type 2 inflammatory response and production of allergen-specific IgE antibodies.
Prevalence
Allergic rhinitis is extremely common, affecting:
- 15% of the US population (approximately 50 million individuals) 1
- Between 10-30% of adults worldwide 2
- Up to 40% of children globally 2
Regarding chronicity:
- 50% of patients experience symptoms for up to 4 months per year
- 20% are symptomatic for more than 9 months annually 2
Clinical Presentation
Cardinal Symptoms
The most common symptoms of allergic rhinitis include:
- Nasal congestion (94.23% of patients) 1
- Rhinorrhea (90.38% of patients) 1
- Postnasal drainage
- Sneezing
- Itching of the eyes, nose, and throat 1, 3
Physical Examination Findings
- Seasonal allergic rhinitis: edematous and pale turbinates
- Perennial/chronic allergic rhinitis: erythematous and inflamed turbinates with serous secretions 1
Associated Conditions
Chronic allergic rhinitis is frequently associated with:
- Asthma
- Eczema
- Chronic or recurrent sinusitis
- Persistent cough
- Tension and migraine headaches 1
- Decreased quality of life
- Decreased sleep quality
- Obstructive sleep apnea
- Absenteeism from work and school
- Impaired performance ("presenteeism") 4
- Otitis media 2
Pathophysiology
The nasal mucosa in allergic rhinitis exhibits:
- Disrupted epithelial barrier allowing allergen penetration
- T-helper type 2 inflammatory response
- Production of allergen-specific IgE
- Highly vascular tissue with changes in blood supply leading to obstruction
- Parasympathetic stimulation increasing nasal cavity resistance and secretions
- Sympathetic stimulation causing vasoconstriction and decreased resistance 1, 4
Classification
Allergic rhinitis is classified based on symptom duration:
- Intermittent: Symptoms occur less than 4 consecutive days/week or less than 4 consecutive weeks/year
- Persistent/Chronic: Symptoms occur more than 4 consecutive days/week and for more than 4 consecutive weeks/year 1
Management Approach
First-line treatments for chronic allergic rhinitis include:
- Allergen avoidance measures
- Pharmacotherapy:
- For mild persistent allergic rhinitis: second-generation H1 antihistamines (cetirizine, fexofenadine, desloratadine, loratadine) or intranasal antihistamines (azelastine, olopatadine)
- For moderate to severe persistent allergic rhinitis: intranasal corticosteroids (fluticasone, triamcinolone, budesonide, mometasone) either alone or combined with intranasal antihistamines 1, 3
- Allergen immunotherapy: the only disease-modifying intervention available, recommended when pharmacologic therapy is ineffective or not tolerated 4, 3