Seasonal Allergic Rhinitis: Diagnosis and Management

Definition

Seasonal allergic rhinitis (SAR) is an IgE-mediated inflammation of the nasal mucosa triggered by airborne allergens present during specific seasons — commonly pollen from trees, grasses, and weeds.

Pathophysiology

Sensitization: Initial exposure to allergen → IgE production → binds to mast cells.
Re-exposure: Allergen cross-links IgE → mast cell degranulation → release of histamine, leukotrienes, prostaglandins.
Early-phase response (minutes): Sneezing, itching, rhinorrhea.
Late-phase response (hours): Nasal congestion from inflammatory cell infiltration.

Epidemiology

Common in children and young adults.
Prevalence up to 20–30% worldwide.
Family history of atopy increases risk.

Clinical Presentation

Symptoms (worsen during specific seasons):

Sneezing
Nasal congestion
Clear watery rhinorrhea
Nasal itching
Ocular symptoms (itchy, watery, red eyes)

Triggers:

Tree pollens (spring)
Grass pollens (summer)
Weed pollens (fall)

Diagnosis

1. History — seasonal pattern, symptom triggers, family history of allergy.2. Physical examination:

Allergic shiners (dark infraorbital circles)
Pale, bluish, edematous nasal mucosa
Clear nasal discharge
Dennie–Morgan folds under lower eyelids
Mouth breathing in severe cases

3. Investigations (if needed):

Skin prick test or serum-specific IgE to identify allergens.
Nasal cytology (eosinophils).
Rule out sinusitis, vasomotor rhinitis, or nasal polyps.

Management

A. Allergen Avoidance

Environmental control: Monitor pollen counts, stay indoors during peak hours (early morning, windy days), use air conditioning with HEPA filters.
Personal protection: Sunglasses outdoors, mask if mowing lawn, shower + change clothes after outdoor exposure.

B. Pharmacotherapy

First-line: Intranasal Corticosteroids (most effective)

Used daily, correct spray technique (slightly outward from nasal septum).Start 1–2 weeks before allergen season for prevention.

Drug	Usual Adult Dose	Max Dose	Notes
Fluticasone propionate (Flixonase®) 50 mcg/spray	1–2 sprays/nostril OD	200 mcg/day	Onset 6–12 h, peak effect ~3 days
Mometasone furoate (Nasonex®) 50 mcg/spray	2 sprays/nostril OD or 1 spray/nostril BID	200 mcg/day	Very low systemic absorption
Budesonide (Rhinocort®) 64 mcg/spray	1 spray/nostril BID or 2 sprays/nostril OD	256 mcg/day	Pregnancy category B — safe option

💡 Pediatric dosing: usually half adult dose; always check product-specific recommendations.

Adjunctive: Oral Second-Generation Antihistamines

Rapid onset (1–3 h), best for sneezing, itching, rhinorrhea.Minimal effect on congestion compared to nasal steroids.

Drug	Adult Dose	Pediatric Dose	Notes
Cetirizine	10 mg PO OD	5–10 mg PO OD (≥2 yrs)	Mild sedation possible
Loratadine	10 mg PO OD	5–10 mg PO OD (≥2 yrs)	Non-sedating
Fexofenadine	120 mg PO OD or 60 mg PO BID	30–60 mg PO BID (≥2 yrs)	Non-sedating, fast onset

Adjunctive: Intranasal Antihistamines

Faster onset than steroids (~15–30 min).Good for as-needed relief or in combo with steroids for severe SAR.

Drug	Adult Dose	Pediatric Dose	Notes
Azelastine 137 mcg/spray	1–2 sprays/nostril BID	1 spray/nostril BID (≥5 yrs)	May cause bitter taste, drowsiness
Olopatadine 665 mcg/spray	2 sprays/nostril BID	Not for <6 yrs	Good ocular + nasal symptom control

Adjunctive: Ocular Antihistamine/Mast Cell Stabilizer Drops

For allergic conjunctivitis symptoms.

Drug	Dose	Notes
Olopatadine 0.1%	1 drop/eye BID	Fast relief, long duration
Ketotifen 0.025%	1 drop/eye BID	OTC in many countries

Combination Therapy

Fluticasone + Azelastine (Dymista®) 50 mcg/137 mcg per spray:
- Dose: 1 spray/nostril BID
- Combines anti-inflammatory + rapid antihistamine effect.
- Useful in severe or uncontrolled SAR despite monotherapy.

C. Saline Nasal Irrigation

Isotonic (0.9%) or hypertonic (1.5–3%) saline rinse.
Dose: 50–250 mL per nostril OD–BID via squeeze bottle or neti pot.
Use before steroid spray to improve drug penetration.

D. Allergen Immunotherapy (AIT)

Subcutaneous (SCIT):
- Weekly build-up injections → monthly maintenance.
- Duration: 3–5 years.
Sublingual (SLIT):
- Daily allergen tablet/drop under tongue.
- Start 3–4 months before season, continue through exposure period.

Indicated for:

Moderate–severe SAR not controlled with optimal pharmacotherapy
Patient preference to reduce long-term drug use
Specific IgE-proven allergen sensitization

Stepwise Summary Table (Adult)

Step	Therapy	Example Dose
1	Intranasal corticosteroid	Fluticasone 1–2 sprays/nostril OD
2	+ Oral antihistamine	Cetirizine 10 mg PO OD
3	+ Intranasal antihistamine	Azelastine 1 spray/nostril BID
4	+ Ocular drops if needed	Olopatadine 1 drop/eye BID
5	Consider AIT	SCIT monthly or SLIT daily

Prognosis

SAR is not life-threatening but can impair quality of life, school/work performance, and predispose to asthma exacerbations.
Good control is achievable with consistent treatment and avoidance strategies.