Contents
What Is Hay Fever (Allergic Rhinitis)?
Seasonal allergic rhinitis — commonly called hay fever — is an IgE-mediated hypersensitivity condition in which the nasal mucosa, eyes, and upper airways become inflamed on exposure to airborne pollen. It affects approximately 1 in 4 adults and 1 in 5 children in the UK, making it one of the most prevalent allergic conditions in the country.
When sensitised individuals inhale pollen, allergen proteins bind to IgE antibodies on mast cells, triggering histamine release and causing the immediate-phase response (sneezing, itch, rhinorrhoea) within minutes. A late-phase response 4–8 hours later drives persistent congestion and mucosal inflammation.
Seasonal vs Perennial
Seasonal rhinitis is driven by outdoor allergens with a defined season (tree pollens, grass, weeds, outdoor moulds). Perennial rhinitis is year-round, typically caused by house dust mite, cat, or dog. Many patients have both.
Quality of Life Impact
Allergic rhinitis impairs sleep, concentration, and productivity significantly. It causes school absences, reduced academic performance in children, and is linked to impaired driving performance. Up to 80% of asthma patients also have allergic rhinitis — and poorly controlled rhinitis worsens asthma.
Main UK Pollen Triggers
- Grass pollen — most common UK trigger (May–Jul)
- Birch pollen — major spring trigger; causes oral allergy syndrome
- Weed pollens — mugwort, plantain, nettle (Jul–Sep)
- Outdoor moulds — Alternaria (Aug–Oct)
UK Pollen Calendar — When Do Pollens Peak?
Understanding when your specific pollen peaks helps predict symptom timing and plan treatment. Warmer, earlier springs (increasingly common with climate change) can advance tree pollen by 2–4 weeks.
| Allergen | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Hazel | ● | ● | ||||||||||
| Alder | ● | ●● | ● | |||||||||
| Birch ★ | ● | ●●● | ● | |||||||||
| Oak / Plane | ● | ●● | ● | |||||||||
| Grass ★★ | ●● | ●●● | ●●● | ● | ||||||||
| Mugwort / Nettle | ● | ●● | ● | |||||||||
| Alternaria / Moulds | ● | ●● | ●● | ● |
★ Birch: also causes oral allergy syndrome to raw apples, hazelnuts, stone fruits. ★★ Grass: most common UK trigger. Timing varies; check the Met Office pollen forecast for real-time data.
Climate change: The UK pollen season is lengthening. Warmer winters advance tree pollen by 2–4 weeks. Higher atmospheric CO₂ increases pollen production and allergenicity. Earlier treatment initiation and longer immunotherapy seasons are increasingly important.
Symptoms & ARIA Severity Classification
Nasal
- Repeated sneezing
- Watery or mucoid runny nose
- Nasal congestion / blockage
- Itchy nose
Eyes (Allergic Conjunctivitis)
- Red, watery, itchy eyes
- Usually bilateral
- Swollen eyelids
- Light sensitivity
Associated
- Itchy throat, palate, or ears
- Headache / facial pressure
- Fatigue and poor sleep
- Worsening asthma on high pollen days
ARIA Severity & Persistence Classification
| Duration | Severity | Definition | First-Line Treatment |
|---|---|---|---|
| Intermittent | Mild | Symptoms <4 days/week or <4 weeks. Sleep and daily activities unaffected. | Oral or intranasal antihistamine. INCS if nasal blockage. |
| Intermittent | Moderate–Severe | Symptoms <4 days/week but impairing sleep or daily activities. | Intranasal corticosteroid + antihistamine. |
| Persistent | Mild | Symptoms ≥4 days/week AND ≥4 weeks, but not significantly impairing life. | Intranasal corticosteroid + regular antihistamine. Review at 2–4 weeks. |
| Persistent | Moderate–Severe | Symptoms ≥4 days/week AND ≥4 weeks AND impairing sleep, work or school. | INCS + antihistamine. Consider allergen immunotherapy. Specialist referral. |
Oral Allergy Syndrome (Pollen–Food Allergy Syndrome)
Oral allergy syndrome (OAS) occurs in pollen-sensitised individuals when raw foods containing structurally similar proteins are eaten. The immune system cross-reacts, causing immediate tingling, itching, or mild swelling of the lips, mouth, and throat. Symptoms typically resolve within minutes and cooked versions of the same food are usually tolerated as heat destroys the cross-reactive proteins.
Birch Pollen Cross-Reactions (Bet v 1)
Most common UK pollen–food syndrome:
- Fruits: raw apple, pear, cherry, plum, peach, apricot
- Nuts: raw hazelnut (Cor a 1), almond
- Vegetables: raw carrot, celery, parsley
- Soya (Gly m 4)
Grass Pollen Cross-Reactions
Grass-sensitised patients may react to:
- Peach, melon, tomato, kiwi
- Wheat via profilins (not true wheat allergy)
Grass pollen AIT can reduce OAS symptoms in grass cross-reactive patients.
When to Seek Testing
Most OAS is mild, but a small minority — particularly those sensitised to heat-stable LTP allergens (e.g. Pru p 3 in peach) or Ara h 2 — can have systemic reactions. ALEX³ molecular testing identifies whether you have low-risk PR-10 cross-reactivity or a higher-risk sensitisation. ALEX³ information →
The United Airways — Rhinitis, Asthma & Sinusitis
The “united airways” concept recognises that allergic rhinitis and asthma are not separate conditions but manifestations of the same underlying airway allergy. Up to 80% of asthma patients have allergic rhinitis, and up to 40% of rhinitis patients have or develop asthma. Uncontrolled rhinitis is an independent risk factor for poorly controlled asthma; treating rhinitis effectively improves asthma control.
Asthma & Pollen Season
Many asthmatic patients experience their worst episodes during the grass pollen season (May–July). Starting intranasal corticosteroids before the season is essential for patients with both conditions.
Sinusitis & Nasal Polyps
Chronic sinusitis and nasal polyps are common complications of poorly controlled rhinitis. Our clinic offers combined allergy and ENT assessment. Early treatment reduces the risk of these complications and of AERD.
Check for Asthma
If you have allergic rhinitis and also experience chest tightness, cough, or wheeze during pollen season or on exercise, spirometry and FeNO testing can assess for concurrent allergic asthma. Tell your consultant about any respiratory symptoms.
Diagnosis & Molecular Pollen Testing
Accurate identification of the specific pollen sensitising you is essential — not just to confirm allergy, but to select the correct immunotherapy allergen. Molecular component testing identifies the specific proteins driving sensitisation.
Skin Prick Testing
First-line, fast, sensitive. Results in 20 minutes. Tests grass, birch, alder, hazel, oak, mugwort, and outdoor moulds. Antihistamines must be stopped 3–7 days before.
Specific IgE Blood Tests
Quantitative sIgE to individual pollen extracts. No antihistamine restriction. Available for 600+ allergens via ImmunoCAP. Useful when SPT is not possible.
ALEX³ Molecular CRD — 300 Components
- Phl p 1 / Phl p 5 — primary grass allergy; confirm SLIT/SCIT candidacy
- Bet v 1 — primary birch sensitiser; explains OAS to apples and hazelnuts
- Profilins (Bet v 2) — low-risk cross-reactive marker
- Distinguishes primary pollen from CCD cross-reactivity for correct AIT selection
Treatment — ARIA Step-Up Approach
Treatment is escalated based on ARIA severity and response. Starting intranasal corticosteroids 2–4 weeks before the pollen season significantly improves their effectiveness.
Intranasal Corticosteroids (INCS) — First-Line
Most effective single treatment. Best for nasal blockage (which antihistamines do not address). Start 2–4 weeks before pollen season. UK products: fluticasone (Flixonase, Avamys), mometasone (Nasonex), budesonide (Rhinocort). Correct technique (aim away from the septum) is essential for efficacy.
Second-Generation Antihistamines — For Sneezing, Itching & Rhinorrhoea
Non-sedating oral antihistamines taken daily throughout the season. UK options: cetirizine 10 mg, loratadine 10 mg, fexofenadine 120–180 mg, desloratadine 5 mg. Do not use first-generation antihistamines (chlorphenamine) — they impair driving and concentration.
Intranasal Antihistamine / Combination Spray
Azelastine nasal spray acts within 15 minutes. Available as a combination product (INCS + azelastine, e.g. Dymista®) with evidence of superiority for moderate–severe rhinitis. For allergic conjunctivitis: antihistamine eye drops (azelastine, ketotifen) or sodium cromoglicate 2% drops.
Leukotriene Antagonists (Montelukast) — Add-On for Rhinitis + Asthma
Useful in patients with both rhinitis and asthma. Less effective than INCS alone for rhinitis. MHRA 2020 guidance: discuss neuropsychiatric side effects with patients before prescribing.
Short-Course Oral Corticosteroids — Last Resort for Severe Exacerbations
A short course of oral prednisolone (5–7 days) may be considered for severe, incapacitating rhinitis during peak season when other treatments have failed. Not for routine use — maximum once or twice per year due to systemic steroid risks.
Still not controlled despite step 3? This is the point at which allergen immunotherapy (AIT) should be considered. AIT addresses the underlying cause and provides long-term disease-modifying benefit. See below.
ENDOFFILE
Allergen Immunotherapy (AIT) — The Only Disease-Modifying Treatment
Allergen immunotherapy (AIT) is the only treatment that modifies the underlying allergic disease. By gradually introducing the allergen, AIT re-programmes the immune system — reducing IgE-mediated responses, inducing regulatory T cells, and producing blocking IgG4 antibodies. Benefits persist for years after completing the course — unlike pharmacotherapy which only suppresses symptoms while being taken.
30–40%
Reduction in symptom scores
~50%
Reduced medication use
Durable
Benefits persist years after completing course
Prevents
New sensitisations & progression to asthma
Correct allergen selection is critical: AIT works best when the primary sensitising pollen is correctly identified via molecular testing (Phl p 1/5 for grass, Bet v 1 for birch). Our consultants use ALEX³ CRD to ensure the right product is chosen. Starting in autumn or winter — at least 4 months before the season — allows the build-up phase to be completed before exposure begins.
Reducing Pollen Exposure — Practical UK Advice
Monitoring Pollen
- Check the Met Office pollen forecast daily
- Pollen peaks 7–11 am and early evening on warm, breezy days
- Lower after rain and on cool, overcast days
Outdoors
- Wear wraparound sunglasses
- Avoid mowing lawns or long-grass areas
- Apply petroleum jelly inside nostrils
- Limit outdoor exercise during peak pollen hours
At Home
- Keep windows closed during high pollen periods
- Shower and wash hair after being outdoors
- Dry laundry indoors or use a tumble dryer
- HEPA air purifiers reduce indoor pollen
Travel & Exams
- Use car pollen filters; replace annually
- Coastal destinations have lower pollen counts
- GCSE / A-level exams coincide with peak grass pollen — plan medication well in advance
Hay Fever in Children
Hay fever is very common in children and adolescents — often underdiagnosed and undertreated. It can significantly impair school attendance, concentration, sleep quality, and exam performance, particularly as the grass pollen season (May–July) coincides with GCSE and A-level examinations.
Treatment in Children
- Intranasal corticosteroids: safe and effective from age 6 (some from age 2–4)
- Non-sedating antihistamines: cetirizine, loratadine from age 2
- Eye drops: sodium cromoglicate safe from any age
- Grazax® SLIT tablets: licensed from age 5
Exam Season Planning
Book a review in January–February to plan treatment before the season starts. Starting INCS 4 weeks before pollen begins significantly improves outcomes. Consider SLIT tablets for long-term benefit.
AIT in Children
AIT in children can prevent new sensitisations and reduce the risk of developing asthma. Grazax® is licensed from age 5. SCIT from age 6–8 in selected cases. Our paediatric allergy consultants assess suitability individually.
Frequently Asked Questions
Trusted Resources
Daily UK pollen count and 5-day forecast by region
International Allergic Rhinitis and its Impact on Asthma guidelines
British Society for Allergy and Clinical Immunology rhinitis guidelines
NICE Clinical Knowledge Summary for allergic rhinitis
Patient information on hay fever, pollen allergy, and finding support
ALEX³ Molecular Pollen Testing →
300 allergens including Phl p 1/5, Bet v 1, and all major UK pollen components
Important Notice
This page provides general educational information only and is not a substitute for individual medical advice. All diagnoses and treatment decisions are made by a qualified consultant following full clinical assessment. In a medical emergency, call 999.
References
- Bousquet J, Schunemann HJ, Togias A, et al. Next-generation ARIA guidelines for allergic rhinitis based on GRADE and real-world evidence. J Allergy Clin Immunol. 2020;145(1):70–80.
- Scadding GK, Kariyawasam HH, et al. BSACI guideline for the diagnosis and management of allergic and non-allergic rhinitis. Clin Exp Allergy. 2017;47(7):856–889. Updated 2022.
- Pfaar O, Bachert C, et al. Guideline on allergen-specific immunotherapy in IgE-mediated allergic diseases. Allergo J Int. 2014;23:282–319. EAACI 2022 update.
- NICE CKS. Allergic Rhinitis. cks.nice.org.uk. Reviewed 2023.
- Met Office. UK Pollen Forecast. metoffice.gov.uk. Accessed June 2026.
Page reviewed: June 2026 | London Allergy and Immunology Centre | privateallergy.uk