Allergic Rhinitis - Treatment

ARIA Classification (Guides Treatment Choice)

• Intermittent - symptoms <4 days/week OR <4 weeks/year
• Persistent - symptoms >4 days/week AND >4 weeks/year
• Severity: Mild vs. Moderate-Severe

ARIA 2008 management algorithm - Scott-Brown's Otorhinolaryngology, p. 1052

Three Pillars of Treatment

1. Allergen Avoidance

2. Pharmacotherapy

Drug Effects at a Glance (Table 91.2 - Scott-Brown's)

A. Antihistamines (H1 Blockers)

• Primary treatment for sneezing, rhinorrhoea, and nasal/ocular itch; little effect on nasal blockage
• 1st-generation (chlorphenamine, diphenhydramine): sedating, rarely used now
• 2nd-generation oral (cetirizine, loratadine, fexofenadine, levocetirizine, desloratadine): non-sedating, once-daily, safe for long-term use including in children; 20-30% symptom reduction
• Topical intranasal antihistamines (azelastine, olopatadine): rapid onset, can be combined with topical steroids; disadvantage is bitter taste and twice-daily dosing
• Best used regularly rather than on-demand; benefit diminishes with prolonged continuous allergen exposure (e.g., perennial disease)

2024 Meta-Analysis update: A systematic review in JACI 2024 confirms that intranasal antihistamines + intranasal corticosteroids as a combination outperform either drug alone.

B. Intranasal Corticosteroids (INCs) - First-Line for Moderate-Severe Disease

• Most effective overall pharmacotherapy - 50-90% symptom reduction vs. 20-30% for oral antihistamines
• Treat all four symptom domains: sneezing, rhinorrhoea, blockage, and impaired smell
• Onset is slow - effect may not be noticed for several days and full benefit takes up to 2 weeks; patients must be counselled about this
• Available agents with doses (Goldman-Cecil):
  • Triamcinolone acetonide - 2 sprays (55 µg) per nostril daily
  • Mometasone furoate - 2 sprays (50 µg) per nostril daily
  • Fluticasone propionate - 2 sprays (50 µg) per nostril daily
  • Budesonide - 2 sprays (32 µg) per nostril daily
• Side effects: epistaxis (usually from poor spray technique, not mucosal atrophy); minor growth retardation noted with beclomethasone in children (not shown with newer agents)
• If adding an antihistamine to an INC, an intranasal antihistamine is preferred over oral

C. Leukotriene Receptor Antagonists (LTRAs)

• Montelukast - as effective as loratadine for nasal symptoms, less effective than topical nasal steroid
• Particularly useful when asthma co-exists with allergic rhinitis (licensed for this indication)
• Variable individual response - a monitored trial is appropriate
• Combination with cetirizine shows inconsistent additive benefit in studies

D. Decongestants

• Topical (xylometazoline): effective for nasal blockage; should not be used for >5-7 days due to risk of rhinitis medicamentosa (rebound congestion)
• Systemic (pseudoephedrine 30-60 mg q4-6h, max 240 mg/24h): treats stuffiness; mild stimulant; may cause rebound congestion and headache; often combined with antihistamines

E. Systemic Corticosteroids

• Reserved for severe, refractory cases or to cover short high-exposure periods
• Prednisolone 20-40 mg/day for short courses
• Depot injectable steroids: effective but not recommended - effects cannot be reversed and risk systemic side effects

F. Sodium Cromoglicate

• Modest efficacy; requires 4x daily dosing (limits compliance)
• No significant side effects - can be used in young children
• Eyedrops effective for ocular itching

G. Ipratropium Bromide

• Specifically for rhinorrhoea (+++); no effect on itch, sneezing, or blockage
• Useful add-on when rhinorrhoea is the dominant symptom

3. Allergen-Specific Immunotherapy (AIT)

• The only disease-modifying/curative option - modifies the underlying immune response
• Both subcutaneous (SCIT) and sublingual (SLIT) routes are effective
• Indicated when pharmacotherapy fails or in patients wishing to reduce long-term medication
• A 2025 umbrella systematic review (PMID 41080605) confirms efficacy across multiple AIT modalities in both children and adults

Treatment Algorithm Summary (ARIA-Based)

Important Considerations

• Unified airway: Treating nasal disease with topical steroids reduces asthma symptoms, and treating lungs may reduce nasal symptoms - assess and treat both together in symptomatic patients
• Always check for asthma, especially with severe or persistent rhinitis
• Intranasal vs. oral treatment meta-analysis (JACI 2024, PMID 39251016) confirms intranasal routes generally superior for nasal outcomes

Sources: Scott-Brown's Otorhinolaryngology Head & Neck Surgery Vol. 1, pp. 1052-1054; Goldman-Cecil Medicine, p. 4167