Asthma and Hay Fever UK: Managing Both Conditions Together
▶ Asthma and hay fever UK
Asthma and hay fever co-exist in ~80% of people with allergic asthma (united airway disease). Hay fever worsens asthma control through nasobronchial reflex, post-nasal drip, and forced mouth breathing. Treating hay fever actively — intranasal corticosteroid sprays from 2 weeks before pollen season — significantly improves asthma outcomes. Montelukast can treat both conditions simultaneously.
If you have both asthma and hay fever, you are in good company — approximately 80% of people with allergic asthma also have allergic rhinitis. The two conditions are not coincidental. They share the same immune mechanism, the same triggers, and — most importantly for your health — inflammation in one worsens inflammation in the other. Managing both conditions together produces better outcomes than treating either in isolation.
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Order Asthma Inhaler →Why Asthma and Hay Fever So Often Go Together
Asthma and hay fever (allergic rhinitis) are both Type 1 (IgE-mediated) allergic conditions. In a genetically susceptible individual, the immune system becomes sensitised to environmental allergens — pollen, dust mites, pet dander — producing IgE antibodies that bind to mast cells lining both the nasal mucosa and the bronchial airways. When exposed to the allergen, mast cells release histamine and other inflammatory mediators in both locations simultaneously.
This shared mechanism means:
- Most people with allergic asthma also have hay fever
- Most people with hay fever are at increased risk of developing asthma
- The severity of hay fever correlates with the severity of allergic asthma
- Treating hay fever actively improves asthma outcomes, and vice versa
This interconnection is recognised clinically as united airway disease — the concept that the upper and lower respiratory tracts function as a single continuous unit from an immunological standpoint.
For the full picture of asthma triggers including allergens, see: Asthma Triggers: A Complete Guide.
How Hay Fever Makes Asthma Worse
Several mechanisms explain why poorly controlled hay fever worsens asthma control:
- Nasobronchial reflex — inflammation in the nasal mucosa triggers reflex bronchoconstriction via the vagus nerve
- Post-nasal drip — inflammatory secretions from the nose drain into the lower airways, directly irritating the bronchial mucosa
- Mouth breathing — nasal congestion forces mouth breathing, bypassing the nose’s warming and filtering function. Cold, unfiltered air reaches the bronchi — a direct trigger for bronchoconstriction
- Systemic inflammatory load — systemic allergic inflammation during hay fever season primes the airways to be more reactive
Clinical data consistently shows that people with poorly controlled hay fever have worse peak flow readings, use their reliever inhalers more frequently, and are significantly more likely to be hospitalised for asthma during pollen season than people whose hay fever is well treated.
Pollen Season: Managing the Asthma-Hay Fever Double Hit
The UK pollen calendar:
| Period | Dominant Pollen | Asthma Risk |
|---|---|---|
| March–May | Tree pollen (birch, ash, oak) | Moderate — particularly for tree-pollen-sensitive individuals |
| May–July | Grass pollen (peak UK season) | High — the dominant trigger for most UK hay fever sufferers |
| July–September | Weed pollen; Alternaria mould spores | High — Alternaria particularly associated with severe asthma attacks |
Thunderstorm asthma: During certain electrical storms (particularly in late summer), rye grass pollen grains rupture under the moisture gradient and electrical charge, releasing ultra-fine starch particles (0.5–2.5 microns) that penetrate deep into the small airways. This can trigger severe, rapid-onset asthma attacks even in people with normally mild asthma. During storms in the pollen season, remain indoors, close windows, and ensure your reliever inhaler is immediately accessible.
For seasonal management in detail, see: Autumn Asthma: Why Asthma Gets Worse in Autumn.
Montelukast: Treating Both Conditions with One Medicine
Montelukast (brand name Singulair) is a leukotriene receptor antagonist (LTRA) with the unusual distinction of being licensed for both asthma and allergic rhinitis. In the NICE asthma treatment ladder, montelukast is a Step 3 add-on option when ICS alone is not providing adequate control.
Leukotrienes are inflammatory mediators that drive both bronchoconstriction and nasal inflammation. Blocking their receptors reduces both upper and lower airway inflammation — making montelukast particularly effective in patients with aspirin-exacerbated respiratory disease and those with concurrent allergic rhinitis.
Important MHRA safety information: In 2019, the MHRA issued guidance on neuropsychiatric reactions associated with montelukast, including sleep disturbances, aggression, depression, and suicidal ideation. These are uncommon but have been reported, particularly in children. Patients and carers should be informed of this risk before starting treatment. Discuss the benefit-risk profile with your prescriber.
For a full guide to montelukast and other Step 3 treatments, see: Asthma Treatment Types: Part 2 — Advanced and Combination Therapies.
Antihistamines and Asthma
Non-sedating antihistamines (cetirizine, loratadine, fexofenadine) are safe and effective for treating the sneezing, itching, and watery eyes of hay fever. However, they have limited effect on nasal congestion and are generally less effective than intranasal corticosteroid sprays for moderate-to-severe hay fever. Using antihistamines alone for hay fever in people with asthma is often suboptimal — the nasal inflammation driving the asthma-hay fever interaction is better addressed by intranasal steroids.
Nasal Corticosteroids and Asthma Control
Intranasal corticosteroid (INCS) sprays — beclometasone (Beconase), fluticasone (Flixonase/Avamys), mometasone (Nasonex), budesonide (Rhinocort) — are the most effective pharmacological treatment for allergic rhinitis and the recommended first-line treatment for moderate-to-severe hay fever. Importantly, optimal INCS use consistently improves asthma outcomes in people with both conditions:
- Reduces reliever inhaler use during pollen season
- Decreases asthma exacerbation rates in people with concurrent allergic rhinitis
- Improves peak flow and lung function during the pollen season
- Reduces emergency department visits for asthma in pollen-sensitive individuals
Start INCS spray 2–4 weeks before your expected pollen season and use daily throughout the season. They take 1–2 weeks to reach full effect — starting too late reduces their benefit significantly.
Allergen Immunotherapy
Allergen immunotherapy (allergy shots or sublingual immunotherapy tablets/drops) gradually desensitises the immune system to specific allergens. It is the only treatment that modifies the underlying allergic disease rather than just managing symptoms. NICE recommends immunotherapy for people with moderate-to-severe hay fever not adequately controlled by pharmacological treatment. Evidence also shows reduction in asthma symptoms in people receiving immunotherapy for hay fever. Discuss referral to an allergy specialist with your GP if standard hay fever treatment is not providing adequate control.
Practical Tips for the Pollen Season
- Check pollen counts daily — the Met Office pollen forecast covers the UK
- Keep windows closed during peak pollen hours (early morning and evening); use air conditioning where possible
- Shower and change clothes after coming in from outdoors on high-pollen days
- Wrap-around sunglasses reduce pollen contact with eyes
- Dry laundry indoors during high-pollen days — pollen sticks to fabric
- Avoid cutting grass or being present when it is cut
- Check your asthma action plan at the start of the season; make sure your prescriptions are up to date
Keep Your Asthma Controlled During Pollen Season
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Order Asthma Inhaler →Frequently Asked Questions
Can hay fever make asthma worse?
Yes — significantly. Hay fever (allergic rhinitis) and asthma share the same underlying allergic mechanism, and inflammation in the upper airway (nose) directly worsens lower airway (bronchial) inflammation. During pollen season, people with both conditions experience substantially increased asthma symptoms and attack risk. Studies show that poorly treated hay fever can double the likelihood of asthma attacks. Treating hay fever actively is an important part of asthma management in people with both conditions.
What is united airway disease?
United airway disease is a clinical concept recognising that the upper airways (nose, sinuses, nasal passages) and lower airways (bronchi, lungs) are anatomically continuous and physiologically linked. Allergic inflammation in the nose (hay fever) directly contributes to lower airway inflammation. The concept explains why treating hay fever well consistently improves asthma outcomes, and why the two conditions are so commonly found together.
Can montelukast treat both asthma and hay fever?
Yes. Montelukast (Singulair) is a leukotriene receptor antagonist licensed for both mild-to-moderate asthma and allergic rhinitis. It is one of the few medicines with evidence for treating both conditions simultaneously, making it particularly useful in patients who have both. Montelukast is a NICE add-on option at Step 3 of asthma treatment, typically added alongside an ICS. It works by blocking leukotrienes — inflammatory mediators involved in both airway inflammation and allergic rhinitis. However, it carries a MHRA safety alert regarding potential neuropsychiatric side effects; discuss with your prescriber.
Should I increase my asthma medication during hay fever season?
Your asthma action plan should guide this. During pollen season, many people with both hay fever and asthma benefit from: ensuring their hay fever is optimally treated (intranasal corticosteroid spray daily from 2–4 weeks before the season starts); maintaining their preventer inhaler consistently; and following their action plan if peak flow begins to drop. Do not increase your preventer dose without prescriber guidance, but do contact your GP or asthma nurse if asthma control deteriorates during pollen season.
What antihistamines are safe to take with asthma?
Non-sedating antihistamines (cetirizine, loratadine, fexofenadine) are safe to take with asthma and are appropriate for treating hay fever alongside asthma medication. Older sedating antihistamines (chlorphenamine/Piriton) are generally not preferred for regular use due to sedation side effects. Intranasal corticosteroid sprays (beclometasone/Beconase, fluticasone/Flixonase, mometasone/Nasonex) are more effective than antihistamines for moderate-severe hay fever and are the first-choice hay fever treatment in people with asthma.
Why do some people get asthma attacks during pollen season?
Pollen directly triggers bronchoconstriction in people with allergic asthma. Combined with the nose-to-lung inflammatory pathway (united airway disease), high pollen counts significantly increase attack risk. Thunderstorm asthma is a specific high-risk phenomenon — during certain electrical storms, rye grass pollen grains rupture, releasing ultra-fine particles (0.5–2.5 microns) that penetrate deeply into the small airways, triggering severe attacks even in people with normally mild asthma.
References
- NICE. Asthma: diagnosis, monitoring and chronic asthma management (NG245). 2024. nice.org.uk/guidance/ng245
- NHS. Asthma. nhs.uk/conditions/asthma
- Asthma + Lung UK. Asthma facts and statistics. asthma.org.uk
- BTS/SIGN. British Guideline on the Management of Asthma (SIGN 158). 2023. sign.ac.uk
- MHRA. Salbutamol (Ventolin Evohaler) summary of product characteristics. medicines.org.uk/emc
- GPhC. Standards for registered pharmacies. pharmacyregulation.org
Medical disclaimer: This article is for informational purposes only and does not constitute medical advice. Asthma inhalers are prescription-only medicines — a clinical consultation is required before they can be dispensed. If you are experiencing a severe asthma attack, call 999 immediately. Always follow the guidance of your prescriber or asthma nurse. In a medical emergency, call 999.