Allergic Rhinitis (Hay Fever)
Managing nasal allergy — from triggers to treatment
Allergic rhinitis is an inflammatory condition of the nasal passages triggered by an allergic response to airborne allergens. It affects up to 30% of adults and 40% of children in the UK. Often called hay fever when triggered by pollen, it can significantly affect quality of life, sleep, work performance and school attendance.
What is Allergic Rhinitis?
Allergic rhinitis occurs when the immune system mounts an IgE-mediated response to normally harmless airborne allergens, triggering the release of histamine and other inflammatory mediators from mast cells in the nasal lining. This causes the characteristic symptoms of nasal congestion, runny nose, sneezing and itching. Allergic rhinitis is classified as seasonal (intermittent) — typically caused by tree, grass or weed pollens — or perennial (persistent) — caused by year-round allergens such as house dust mites, pet dander or mould spores. Many patients have mixed intermittent and persistent symptoms. Allergic rhinitis is strongly associated with other atopic conditions including asthma (present in up to 40% of allergic rhinitis patients), eczema and food allergy.
Triggers
The most common triggers of seasonal allergic rhinitis include grass pollen (June–July, the most prevalent UK allergen), tree pollen (February–May, especially birch and oak), and weed pollen (August–September). Perennial triggers include house dust mites (Dermatophagoides pteronyssinus), cat and dog dander, cockroach allergens, and Alternaria and Aspergillus mould spores. Occupational allergens (flour, latex, animal dander in laboratory workers) can cause occupational rhinitis. Trigger identification helps to guide avoidance strategies and targeted immunotherapy. Weather conditions also affect pollen counts — high counts occur on warm, dry, windy days; rain temporarily reduces symptoms by washing pollen out of the air.
Symptoms
The hallmark symptoms of allergic rhinitis are: nasal congestion (blocked nose), rhinorrhoea (runny nose — typically clear watery discharge), nasal itching (pruritus), and sneezing attacks, often occurring in bursts. These nasal symptoms are accompanied in many patients by ocular symptoms (allergic conjunctivitis) — itchy, red, watery eyes. Patients may also experience itching of the palate, throat or ears. Persistent nasal obstruction leads to mouth breathing, snoring, disrupted sleep and daytime fatigue — significantly impacting quality of life. Nasal polyps may develop in patients with long-standing perennial rhinitis and may require separate management.
Diagnosis
Diagnosis is primarily clinical, based on history and symptom pattern. Investigations to identify specific allergens include skin prick testing (SPT) — the standard first-line investigation, which introduces a small amount of allergen into the skin and measures the wheal response after 15 minutes. A wheal ≥3 mm larger than the negative control indicates sensitisation. Serum specific IgE testing (RAST or ImmunoCAP) can identify sensitisation to individual allergens and is used when SPT is not available or is contraindicated (e.g., severe eczema, antihistamine use, risk of anaphylaxis). Total serum IgE is not diagnostic on its own. Nasal endoscopy may be performed if structural abnormalities (deviated septum, polyps) are suspected. Referral to an NHS allergy clinic or ENT may be appropriate for complex or severe cases.
Treatment
NICE CG134 recommends intranasal corticosteroids (INCS) as the most effective first-line treatment for allergic rhinitis, particularly for nasal congestion. Examples include mometasone furoate (Nasonex) 100 micrograms per nostril once daily — available OTC and preferred for minimal systemic absorption — and fluticasone propionate (Flixonase) 100 micrograms per nostril once daily. INCS should be started 2 weeks before the pollen season for best effect. Non-sedating oral antihistamines — loratadine 10 mg OD or cetirizine 10 mg OD (both available OTC) — are effective for rhinorrhoea, sneezing and itching but less effective for congestion; they can also be used as needed. Nasal antihistamines (azelastine) act faster than oral. Short-term nasal decongestants (xylometazoline, oxymetazoline) relieve congestion acutely but must not be used for more than 7 days due to rebound congestion (rhinitis medicamentosa). Allergen immunotherapy (AIT) — sublingual immunotherapy (SLIT) tablets (e.g. Grazax for grass pollen) or subcutaneous immunotherapy (SCIT, available in specialist centres) — is the only treatment that modifies the underlying allergic disease and can provide long-lasting benefit after treatment completion. NICE recommends AIT for moderate-to-severe allergic rhinitis inadequately controlled by first-line treatment.