• If you think you may have an allergy, see your doctor for allergy testing.
  • You could also keep a symptom diary to record the times and situations when your asthma is worse and to help identify triggers.
  • Identifying and reducing exposure to avoidable asthma triggers may improve your asthma control.
  • Make sure you have an up-to-date asthma action plan, and continue to use your asthma medication as directed.

People with asthma have sensitive airways that can react to different triggers in their environment. For some people with asthma, ongoing exposure to triggers can cause continued inflammation (swelling and redness) and excess mucus production in the airways, making their asthma worse. 

Atopy is the genetic tendency to develop allergic conditions. Many people with asthma are atopic and have an increased risk of developing other allergic conditions. If you are atopic, some allergens can be trigger factors that can cause increased asthma symptoms and reduced asthma control when you are exposed to them. 

Other allergic reactions may include: 

  • allergic rhinitis (hay fever) – sneezing, blocked and runny nose, itchy eyes and throat
  • eczema – dry, red, itchy skin
  • hives – skin rashes
  • anaphylaxis – a severe form of an allergic reaction that is potentially life-threatening.

Identifying asthma triggers

Asthma is often initially recognised by people when symptoms get worse in response to particular allergens or other triggers. Everyone's asthma is different, and everyone has different triggers. For most people with asthma, however, triggers are only a problem when their asthma is not well-controlled. 

Identifying and reducing exposure to your allergen triggers may improve your asthma control and make your asthma symptoms easier to manage, but it is important you talk with your doctor about how to manage the allergen. Your doctor may prescribe medication and advise how to reduce your exposure to your allergen triggers if appropriate. They may also update your asthma action plan

If you think you are suffering from an allergy, keep a symptom diary to record the times and situations when your asthma is worse and to help identify triggers. Then see your doctor for advice.

While allergy avoidance measures may help to reduce exposure to allergen triggers, make sure you continue to use your asthma medication as directed and follow your asthma action plan. This is both a cheaper and more effective way of dealing with your asthma.

Types of asthma triggers

There are two types of triggers that can flare up someone's asthma: 

  • avoidable triggers – including cigarette smoke, allergens, irritants (such as perfumes, chemicals, cold/dry air, smoke and paint) certain medicines and dietary triggers
  • unavoidable triggers (triggers that cannot or should not be avoided) – such as exercise, laughter, respiratory tract infections, certain medicines, certain medical conditions, extreme emotions, hormonal changes, pregnancy and sexual activity.

One of the most common triggers for asthma flare-ups is exercise and physical activity. This is one trigger not to avoid if possible, as exercise is an essential part of a healthy lifestyle. 

The Australian Asthma Handbook has more information about asthma triggers.

Allergens that trigger asthma

Allergens are any substance that can bring on an allergic reaction. An allergic reaction occurs when your immune system reacts to substances in the environment that are harmless to other people. If you are allergic to something, eating it, inhaling it, injecting it or touching it can bring on an allergic reaction.

Asthma symptoms can occur when an allergen is breathed into the lungs of a sensitive person. This leads to swelling of the lining of the airways and tightening of the muscles around the airway, which causes narrowing of the airway and difficulty in breathing.

The most common allergic triggers for asthma are house dust mites, pets (animal dander), pollen and mould. Thunderstorms are a rare allergic asthma trigger.

Allergy testing for asthma

There are two main allergy tests that can help to pinpoint your allergens – skin prick tests and blood tests for serum specific IgE.

Skin prick tests are performed at your doctor's office or medical clinic, or by an allergy specialist. Small amounts of different allergen solutions, such as pollen extract, are pricked into your skin along your arm or on your back. If you are sensitised to the allergen the skin swells or develops a welt.

Serum specific IgE allergy tests are blood tests that detect specific IgE antibodies. These antibodies are made by your body’s immune system against allergens such as dust mites, pollens, animal dander, moulds and foods.

These skin and blood tests are not conclusive in determining asthma triggers. Just because your skin and blood react to an allergen, doesn't mean your lungs will too. Think of these tests as a helpful starting point. Tests such as these should only ever be performed under the guidance of a doctor or allergy specialist.

Where to get help 


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Managing asthma

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This page has been produced in consultation with and approved by: Asthma Australia

Last updated: September 2017

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