The nose and the lungs share a continuous lining and a common allergic mechanism. Allergic rhinitis and asthma frequently coexist, and pollen exposure that inflames one tends to affect the other.
The practical consequence is that treating hay fever properly is part of asthma control, not a separate cosmetic exercise.
Why Pollen Season Is Risky for Asthma
- Nasal congestion forces mouth breathing, so air reaching the lungs is not warmed, humidified or filtered by the nose
- Post-nasal drip irritates the airway and provokes coughing
- Systemic allergic inflammation affects the lower airway directly
- Disturbed sleep from congestion worsens asthma control
Thunderstorms during high grass pollen are a recognised trigger for clusters of severe asthma attacks — the mechanism involves pollen grains rupturing into smaller particles that penetrate deeper into the airway.
What to Do Before the Season
- Check your asthma is well controlled before pollen season, not during it
- Start hay fever treatment early — two to four weeks before your usual onset
- Use your preventer inhaler consistently. This is the one that matters and the one people quietly drop when they feel well
- Have an up-to-date asthma action plan and know what to do if symptoms escalate
- Carry your reliever
Where Montelukast Fits
Montelukast is a leukotriene receptor antagonist taken as a daily tablet. It is used for asthma and also for allergic rhinitis, which makes it appealing where both coexist — one tablet addressing both.
It is generally less effective for nasal symptoms than a steroid nasal spray, so it is not a first-line hay fever treatment on its own.
The safety warnings
An MHRA review concluded that the risk of neuropsychiatric reactions with montelukast had not changed but was not sufficiently well known, and required boxed warnings in every UK patient information leaflet.
Reported reactions include sleep disorders, depression, anxiety and behaviour changes, with hallucinations and suicidal thoughts rare. Around 44 million prescriptions have been issued in the UK since 1998, with 1,223 reports of suspected neuropsychiatric adverse reactions — rare, but worth recognising.
In children this matters particularly, since a child is unlikely to connect a mood or behaviour change to a tablet. Report changes promptly rather than waiting to see whether they settle.
The Sequence That Usually Works
- Asthma preventer inhaler, taken properly and consistently
- Non-sedating antihistamine, started before the season
- Steroid nasal spray, used daily with correct technique
- Review with a clinician if symptoms persist — combination nasal sprays, montelukast, or immunotherapy for severe allergy are all possibilities
Immunotherapy
For people with severe, poorly controlled pollen allergy, allergen immunotherapy treats the underlying allergy rather than the symptoms. NICE has recommended a birch pollen immunotherapy tablet for adults with severe allergic rhinitis, and subsequently extended guidance to children aged 5 to 17. In children there is also evidence it may reduce the risk of going on to develop asthma.
It is a three-year commitment and requires specialist assessment, but for someone whose pollen season repeatedly destabilises their asthma, it is a different order of intervention.
When to Seek Help Urgently
Increasing reliever use, night-time waking with symptoms, breathlessness affecting normal activity, or a peak flow falling below your usual range are all reasons to act rather than wait for the season to end.