Possible severe allergic reaction or airway emergency
Seek Emergency Care Immediately If
- There is swelling of the tongue, throat, mouth or face with difficulty breathing or swallowing.
- The voice becomes suddenly hoarse, breathing becomes noisy, or there is choking or rapidly worsening wheeze.
- The person becomes faint, confused, very drowsy, pale, blue or grey, or collapses.
- Breathing symptoms occur with a widespread itchy rash, repeated vomiting, severe abdominal symptoms or rapidly increasing swelling.
- A known severe allergy has been triggered and the person’s clinician-written emergency plan indicates urgent action.
- A child is struggling to breathe, unable to speak or feed normally, unusually quiet or floppy, or changing colour.
A severe allergic reaction can progress quickly and may occur without obvious skin changes. Follow the patient’s prescribed emergency plan while arranging emergency medical help; do not wait to see whether it settles.
What Is an Allergen?
An allergen is a substance that triggers a specific immune response in a sensitised person. Airborne allergens can be inhaled or settle on the eyes and nasal lining. The same exposure may affect one person strongly and another not at all.
Allergen and irritant are not the same
Smoke, perfume, incense, cleaning fumes and pollution can trigger real symptoms by irritating sensitive airways without a specific allergic immune response. Standard allergy tests do not diagnose every irritant reaction.
Common Symptoms
- Repeated sneezing, often in bursts.
- An itchy nose, palate, throat or ears.
- Clear watery nasal discharge or persistent blockage.
- Itchy, red, swollen or watery eyes.
- Reduced sense of smell, throat clearing or mucus felt at the back of the throat.
- Cough, wheeze, chest tightness or breathlessness when the lower airway is involved.
- Poor sleep, daytime tiredness, reduced concentration or impaired school and work performance.
Seasonal and Year-Round Patterns
Seasonal pattern
Symptoms cluster during a particular flowering, pollen, harvest, weather or mould season and improve outside that period.
Year-round pattern
Symptoms persist or recur indoors and may relate to dust mites, dampness, mould, animals, cockroaches or occupational exposure.
Seasons vary by region and climate. A diary of place, timing, weather, work, cleaning, animal contact and symptom change can be more informative than relying on a generic pollen calendar from another country.
Common Airborne Allergens
- House-dust mites living in bedding, upholstered material and indoor dust.
- Pollen from selected grasses, weeds and trees.
- Mould spores associated with damp indoor or outdoor environments.
- Proteins from animals, carried in skin flakes, saliva and other material—not only fur.
- Cockroach and selected pest allergens.
- Workplace allergens such as flour, wood, animal proteins, plant material or selected industrial substances.
A person may be sensitised to several substances but have clinically important symptoms from only some of them.
Allergy, Cold or Sinus Infection?
Yellow or green mucus does not by itself prove a bacterial infection, and allergy can coexist with infection or a structural nasal problem.
How Are Respiratory Allergies Linked to Asthma?
The nose and lower airways form one connected respiratory system. Allergic rhinitis is common in people with asthma, and a relevant airborne allergen can trigger cough, wheeze, tightness or breathlessness in a sensitised person.
Nasal symptoms do not automatically prove asthma. Recurrent lower-airway symptoms require their own assessment, including objective breathing tests whenever practical.
How Is the Diagnosis Made?
Many cases are recognised from a consistent history and examination. The clinician asks what happens, how quickly, where, during which season or task, and whether symptoms improve away from the suspected exposure.
- Nasal, eye, throat and chest symptoms are considered together.
- Home, school, work, animal, dampness and smoke exposure are reviewed.
- The nose, throat, chest, skin and eyes are examined as relevant.
- Asthma testing is arranged when cough, wheeze, tightness or breathlessness suggests lower-airway involvement.
- Allergy testing is chosen when identifying a trigger will change practical management.
What Do Allergy Tests Show?
What Does a Positive Test Mean?
A positive skin or blood test means the immune system is sensitised to that substance. Clinical allergy is present only when the result matches a convincing symptom pattern after relevant exposure.
Test strength does not reliably predict reaction severity
A larger skin reaction or higher blood-test value may increase confidence in sensitisation, but it cannot by itself predict exactly how severe a future reaction will be. Interpretation belongs with the clinical history.
When Is Testing Particularly Useful?
- The suspected trigger is uncertain and symptoms significantly affect daily life.
- Knowing the trigger would guide a realistic exposure-reduction plan.
- Asthma appears linked to a home, seasonal, animal or occupational exposure.
- Specialist desensitisation is being considered.
- The history is complex, severe or inconsistent with routine allergic rhinitis.
Testing is not always required for a clear, mild pattern. Broad panels create incidental positives that may lead to unnecessary fear, expense or avoidance.
Which Tests Need Caution?
Hair analysis, electrodermal testing, unselected “food sensitivity” panels and several commercial wellness tests are not substitutes for validated allergy assessment. Food testing is not routinely used to explain isolated chronic nasal symptoms without a convincing food-reaction history.
Do not remove multiple foods, abandon a pet, leave a job or make costly building changes solely because of an online panel or isolated positive result.
How Is Exposure Reduction Planned?
The most useful plan targets a clinically relevant trigger and combines feasible measures. No single product can make a home completely “allergy-free.”
- Repair persistent water entry and address visible dampness or mould safely.
- Reduce tobacco smoke, incense, strong fumes and other airway irritants.
- Use bedding, cleaning and humidity measures selectively when dust mites are clinically relevant.
- Match pollen precautions to local timing and the patient’s actual seasonal pattern.
- Discuss realistic animal-exposure measures when symptoms, contact and testing agree.
- Document workplace tasks and seek occupational assessment before major employment decisions.
What Does Long-Term Care Include?
- A clear diagnosis and separation of allergy, irritant sensitivity, infection and structural problems.
- An individual prescribed plan for nose, eyes and airways according to the affected sites.
- Technique review for any prescribed nasal or inhaled device.
- Assessment and objective monitoring when asthma is present or suspected.
- Targeted exposure reduction without unrealistic or harmful restrictions.
- Specialist assessment for selected severe, complex or occupational allergy.
Specialist desensitisation may be considered for selected patients after the responsible allergen and clinical pattern have been confirmed. It is a supervised medical pathway, not a home treatment.
Respiratory Allergies in Children
Allergic rhinitis can disturb sleep, attention, school performance and activity. Mouth breathing, snoring, hearing difficulty, repeated wheeze or poor growth may require broader assessment rather than an allergy label alone.
Testing should be selected for the child’s actual history. Positive results without symptoms should not create broad food, school, animal or activity restrictions.
When Is ENT or Higher-Centre Referral Appropriate?
- Symptoms remain severe or unclear despite appropriate assessment and a supervised plan.
- There is one-sided blockage, recurrent bleeding, marked smell loss, a suspected polyp or another structural concern.
- Asthma remains poorly controlled or severe lower-airway reactions occur.
- Occupational allergy, a complex systemic reaction or specialist desensitisation is being considered.
- A child has significant sleep, hearing, growth or recurrent chest problems.
- Required allergy, immunology or multidisciplinary facilities are beyond local capability.
Common Myths
Frequently Asked Questions
What is the difference between respiratory allergy and allergic rhinitis?
Allergic rhinitis specifically affects the nose. Respiratory allergy is a broader patient-friendly term that may include nose, eye, throat and allergy-triggered lower-airway symptoms.
Is hay fever possible in a tropical climate?
Yes. The term refers to seasonal allergic rhinitis, not to hay or fever. Local pollen, mould and seasonal patterns vary by climate.
How can I tell allergy from a cold?
Itching, repeated sneezing, watery eyes and recurrence with exposure favour allergy; fever, body ache and a short self-limited course favour infection. Overlap occurs.
Can respiratory allergies cause cough?
Yes. Nasal inflammation, throat irritation and allergy-triggered asthma can contribute, but persistent cough also has many non-allergic causes.
Does allergic rhinitis mean I have asthma?
No. They commonly coexist, but cough, wheeze, tightness or breathlessness needs a separate asthma assessment with objective testing when practical.
What does a positive skin test mean?
It shows sensitisation to that allergen. It becomes clinically meaningful only when the real-life exposure causes a matching symptom pattern.
Is a blood allergy test better than a skin test?
Neither is universally better. The choice depends on the clinical question, skin condition, current prescribed treatments, safety and local expertise.
Does a higher allergy-test number mean a more severe reaction?
No. It can strengthen evidence of sensitisation in context but does not reliably predict reaction severity.
Do I need a test for every possible allergen?
No. Testing should be selected from the history. Broad panels often identify sensitisation that has no clinical relevance.
Should food allergy panels be used for a blocked or runny nose?
Not routinely. Food testing is guided by a convincing history of symptoms after eating a particular food, not isolated chronic nasal symptoms.
Are reactions to perfume and smoke true allergies?
They are often irritant reactions rather than specific allergies, although they can still trigger important nasal or asthma symptoms.
Can a “hypoallergenic” pet guarantee no symptoms?
No. Relevant animal proteins are carried in skin flakes, saliva and other material, so coat type alone cannot guarantee absence of exposure.
Can mould cause respiratory allergy?
Yes in sensitised people, and damp buildings can affect respiratory health through several pathways. Persistent water entry and visible dampness deserve correction.
Can respiratory allergy be cured permanently?
The tendency may persist, but symptoms can often be controlled with a correct diagnosis, targeted exposure measures and an individual prescribed plan. Selected patients may be assessed for specialist desensitisation.
When is higher-centre referral appropriate?
Referral may be needed for severe or uncertain disease, poorly controlled asthma, occupational allergy, systemic reactions, complex childhood problems or specialist testing and desensitisation.