What is Allergic Rhinitis?
Allergic rhinitis, commonly called hay fever, is inflammation of the nasal lining caused by an immune reaction to airborne allergens such as pollen, dust mite, pet dander, or mould. It causes sneezing, a runny or blocked nose, and itchy eyes, nose, and throat. Intranasal corticosteroid sprays are the most effective single treatment for persistent symptoms.
Key takeaways
- Allergic rhinitis is an immune reaction, not an infection — there is no fever and symptoms track exposure.
- Itching of the nose, eyes, and palate is the feature that most reliably distinguishes it from a cold.
- Intranasal corticosteroid sprays are more effective than antihistamines for congestion, but need daily use and correct technique.
- Poorly controlled nasal allergy worsens asthma control, sleep quality, and daytime concentration.
- Allergen immunotherapy can modify the underlying allergy rather than just suppressing symptoms.
Overview
Allergic rhinitis affects a large share of the population and is frequently dismissed as trivial, which underestimates its impact. The immune system misidentifies a harmless airborne protein as a threat, produces IgE antibodies against it, and on subsequent exposure triggers mast cells in the nasal lining to release histamine and other mediators. The immediate result is sneezing, itching, and watery discharge; a later-phase response several hours afterward brings congestion and ongoing inflammation.
Beyond the obvious nuisance, poorly controlled allergic rhinitis disturbs sleep, impairs concentration and school or work performance, and makes asthma harder to control — the upper and lower airways behave as a connected system. Treatment is effective when matched to the symptom pattern and used correctly, but two common problems undermine it: using antihistamines alone for congestion, and using nasal sprays with poor technique or only when symptoms are already severe.
What Allergic Rhinitis is
Allergic rhinitis is classified by pattern rather than by season. Intermittent means symptoms on fewer than four days a week or for less than four weeks; persistent means more than that. Severity is graded by whether sleep, daily activities, work or school, and general wellbeing are affected. Seasonal patterns usually reflect pollen from trees, grasses, or weeds; perennial patterns usually reflect house dust mite, pet dander, mould, or cockroach.
It commonly coexists with allergic conjunctivitis, asthma, eczema, and chronic rhinosinusitis with or without nasal polyps. Non-allergic rhinitis produces similar nasal symptoms without an IgE-mediated cause, is triggered by irritants, temperature change, or medicines, and typically lacks itching — which matters because allergy treatments work less well for it.
Common symptoms
Symptoms appear on exposure to a trigger and involve the nose, eyes, and often the throat and ears.
- Repeated sneezing, often in bouts
- Clear, watery nasal discharge
- Nasal congestion or blockage, frequently worse at night
- Itching of the nose, roof of the mouth, throat, or ears
- Itchy, watery, red eyes
- Postnasal drip and throat clearing
- Reduced sense of smell
Less common symptoms
- Fatigue and poor concentration from disturbed sleep
- Dark circles under the eyes (allergic shiners) from venous congestion
- A horizontal crease across the nose from repeated upward rubbing, especially in children
- Ear fullness or popping from Eustachian tube dysfunction
- Cough and worsening asthma symptoms
- Recurrent sinus infections
Risk factors
- Family history of allergy, asthma, or eczema — atopy is strongly inherited
- Personal history of eczema or food allergy in early childhood — part of the atopic progression
- Exposure to house dust mite, pets, mould, or cockroach in the home
- High pollen exposure regions and lengthening pollen seasons associated with climate change
- Tobacco smoke and air pollution exposure — irritate and sensitise the airway lining
- Occupational exposure to flour, latex, animals, or laboratory chemicals
- Being born during a high-pollen season — a modest but repeatedly observed association
- Male sex in childhood, shifting toward female predominance in adulthood
Causes
The underlying cause is IgE-mediated sensitisation. On first exposure to an allergen, the immune system produces specific IgE antibodies that coat mast cells in the nasal lining. On later exposures the allergen cross-links those antibodies, mast cells degranulate, and histamine, leukotrienes, and other mediators produce the immediate symptoms. A late-phase response several hours later recruits eosinophils and other cells, driving the congestion and ongoing inflammation.
Why some people sensitise and others do not involves genetics, early-life microbial exposure, air pollution, and barrier function of the airway lining. The observation that children raised on farms with diverse microbial exposure have lower rates of allergic disease has been replicated repeatedly, though it has not translated into a simple preventive intervention.
How it is diagnosed
Diagnosis is usually clinical, with testing used to identify specific triggers when that will change management.
| Test or assessment | What it looks at |
|---|---|
| Clinical history | The pattern of symptoms, their timing relative to seasons and environments, and the presence of itching are the most informative parts of the assessment. |
| Skin prick testing | Small amounts of allergen are applied to the skin and reactions measured after about 15 minutes. Fast, sensitive, and useful for identifying specific triggers. |
| Specific IgE blood testing | Measures antibodies to particular allergens. Used when skin testing is impractical, such as with extensive eczema or antihistamine use that cannot be stopped. |
| Nasal examination | Looks for the pale, swollen turbinates typical of allergy and for nasal polyps or structural problems that would change treatment. |
| Nasal endoscopy or sinus CT | Reserved for suspected chronic rhinosinusitis, polyps, or symptoms not responding as expected. |
| Spirometry | Considered where cough, wheeze, or breathlessness suggests coexisting asthma, which is common with allergic rhinitis. |
Treatment overview
Treatment combines reducing exposure with medication matched to symptoms, and immunotherapy for persistent or severe disease. The categories below describe available approaches; product choice and dosing rest with your clinician or pharmacist.
Allergen avoidance measures
Practical reduction of exposure — dust mite covers, pollen-aware routines, pet management, and mould control. Effects are modest but useful alongside treatment.
Intranasal corticosteroid sprays
The most effective single treatment for persistent symptoms, particularly congestion. They work best used daily and take several days to reach full effect.
Oral and intranasal antihistamines
Fast-acting relief of sneezing, itching, and runny nose. Non-sedating second-generation oral options are preferred over older sedating types.
Leukotriene receptor antagonists
An option particularly where asthma coexists, though generally less effective than nasal steroids for nasal symptoms and carrying neuropsychiatric warnings.
Saline nasal irrigation
Rinsing with saline reduces symptoms and improves the effectiveness of nasal sprays. Only sterile, distilled, or previously boiled water should be used.
Eye treatments
Antihistamine or mast cell stabiliser eye drops for allergic conjunctivitis that persists despite nasal treatment.
Allergen immunotherapy
Subcutaneous injections or sublingual tablets given over several years that retrain the immune response. It can modify the disease and provide lasting benefit after treatment ends.
Lifestyle considerations
- Start nasal steroid treatment a couple of weeks before your usual season rather than waiting for symptoms.
- Learn correct nasal spray technique: aim slightly outward toward the ear, not at the septum, and do not sniff hard.
- Rinse with saline before using a nasal spray to clear mucus and improve delivery.
- Shower and change clothes after being outdoors during high pollen counts.
- Keep windows closed during peak pollen times and use air conditioning where available.
- Use allergen-proof covers on mattresses and pillows and wash bedding weekly in hot water for dust mite allergy.
- Keep pets out of the bedroom if you are sensitised to their dander.
- Avoid decongestant nasal sprays for more than a few days — rebound congestion develops quickly.
Prevention
- Allergic rhinitis cannot be reliably prevented, but exposure and severity can be reduced.
- Avoid tobacco smoke exposure, particularly in childhood.
- Reduce indoor allergen load through ventilation, humidity control below about 50%, and dust mite measures.
- Treat early and consistently rather than intermittently, which reduces the inflammation that drives worsening symptoms.
- Consider immunotherapy for persistent symptoms — it may reduce the later development of asthma in some children.
- Manage coexisting asthma actively, since upper and lower airway inflammation reinforce each other.
Warning signs and when to get help
Signs that need emergency care
If you believe you are experiencing a medical emergency, call emergency services immediately (911 in the United States).
- Difficulty breathing, throat tightness, or swelling of the lips, tongue, or face — possible anaphylaxis, use epinephrine if prescribed and call emergency services
- Sudden widespread hives with dizziness, vomiting, or collapse
- Severe asthma symptoms with inability to speak in full sentences
Signs that warrant a prompt appointment
These are not emergencies, but they are worth a call to your clinician rather than a wait-and-see.
- Symptoms persisting despite regular treatment for several weeks
- One-sided nasal blockage, bloody discharge, or facial pain — needs examination
- Complete loss of smell that does not recover
- Recurrent sinus infections
- New wheeze, chest tightness, or night-time cough suggesting asthma
- Sleep disruption or daytime tiredness caused by nasal blockage
Questions to ask a healthcare professional
Take these to your next appointment — or build an agenda with the Appointment Prep tool.
- Are my symptoms allergic, or could this be non-allergic rhinitis?
- Would allergy testing change how we treat this?
- Can you check my nasal spray technique?
- Should I be using treatment daily through the season rather than as needed?
- Am I a candidate for immunotherapy, and what would that involve?
- Could my nasal symptoms be affecting my asthma control?
- Which over-the-counter options are appropriate for me, and which should I avoid?
- Are any of my other medicines making nasal symptoms worse?
Frequently asked questions
How can I tell hay fever from a cold?
Itching of the nose, eyes, and palate points strongly to allergy; colds rarely itch. Colds usually last around a week, often come with a sore throat or mild fever, and produce thicker discharge over time, while allergy symptoms persist as long as exposure continues.
Why is my nasal spray not working?
The two most common reasons are technique and timing. Nasal corticosteroids take several days to a couple of weeks for full effect and need daily use, not as-needed use. Aiming the spray outward toward the ear rather than at the septum also improves delivery and reduces nosebleeds.
Are decongestant sprays safe to use regularly?
No. Topical decongestant sprays work quickly but cause rebound congestion if used beyond about three days, which can lead to a cycle of worsening blockage and continued use. They are for very short-term use only.
What is immunotherapy and is it worth it?
Immunotherapy delivers gradually increasing amounts of the allergen by injection or under-the-tongue tablet over three to five years, retraining the immune response. It is the only treatment that modifies the underlying allergy, with benefits that can persist after stopping, and it is worth considering for persistent or severe symptoms.
Does allergic rhinitis affect asthma?
Yes. The upper and lower airways function as one system, and untreated nasal allergy is associated with worse asthma control and more exacerbations. Treating the nose often improves the chest, which is why clinicians ask about both. See our asthma page for more.
Sources
- AAAAI — Rhinitis — Specialist patient information on allergy and testing
- NIAID — Allergic Diseases — NIH overview of allergy mechanisms and research
- CDC — Allergies — Pollen, allergen exposure, and environmental trends
- MedlinePlus — Hay Fever — Consumer summary and treatment links
Health Captain links to primary public-health and clinical sources so you can read the original material yourself. See our sources policy.