Asthma triggers are substances, conditions or activities that lead to symptoms of asthma.Asthma symptoms include difficulty breathing, coughing, wheezing and shortness of breath. These symptoms can become severe and lead to a life-threatening asthma emergency.Asthma symptoms can be triggered by substances that cause allergic reactions or by conditions or activities not related to allergies. If your child or a child in your care has asthma, some childcare centres and schools are recognised for creating an asthma-friendly environment.Ask your doctor about how you can avoid or reduce exposure to triggers of your asthma symptoms. You should also ask your doctor to update your asthma action plan each year.
Allergy triggers for asthma
Allergies are a common cause of asthma symptoms and the timing will depend on the substances you are allergic to. For example, if you are allergic to pollen, your symptoms may be worse in spring, whereas if you are allergic to house dust mites, you will have a risk of symptoms all year round.
The allergic symptoms produced vary from person to person and can include hay fever, skin reactions, asthma or a life-threatening severe allergic reaction (anaphylaxis).
If you are allergic to a substance that causes your asthma symptoms to flare up, you can take action to avoid or reduce exposure to the allergy trigger.
Common allergy triggers of asthma symptoms
Allergy triggers that can lead to asthma symptoms include:
- dust mites
- animal dander – especially from cats and dogs
- mould spores – which can be worse at certain times of the year
- pollen – from grass, weeds and trees and usually occurring seasonally
- workplace substances – such as latex, wood dust or flour.
Food allergies do not usually cause asthma themselves, but people with food allergies can be more susceptible to symptoms of asthma. Also, sulphites in food and drink may cause asthma symptoms.
Reducing exposure to substances that trigger your allergies and asthma symptoms can help you to control your asthma. Even if you try to avoid allergy triggers of your asthma, you should speak with your doctor about taking your asthma medication as an effective way to control your asthma.
Tips to reduce exposure to animal dander
The best strategy to reduce the risk of an allergic reaction is to avoid contact with the type of animal that causes your allergy. This can be difficult if you have a pet or if you visit another household where there is a pet.
Tips that can help to reduce the risk of exposure to animal allergy triggers include:
- making sure that furred animals do not enter your home
- finding an existing pet a new home
- keeping your pet in one area of the house
- making sure your pet does not enter your bedroom or sleep on your bed
- using high-efficiency air cleaners
- avoiding carpets or rugs, especially in bedrooms
- washing your pet every week
- brushing or groom pets outside
- vacuuming regularly.
Tips to reduce exposure to house dust mites
To reduce exposure to house dust mites:
- choose bedding, such as mattress and pillow protectors, that are mite resistant and wash them regularly
- wash bed linen each week in water above 60 ºC
- use blankets and doonas that can be washed
- avoid carpet and rugs where possible
- vacuum each week using a vacuum with a high-efficiency particulate air (HEPA) filter
- clean hard floors weekly with a damp or anti-static cloth, mop or a steam mop
- dust weekly using a damp or anti-static cloth
- avoid textured or cloth upholstery on furniture – leather, wood and vinyl are best
- consider using venetian blinds and flat blinds, if affordable – they are easier to clean than cloth curtains.
In general, washing in hot water above 60 ºC both kills dust mites and removes the allergic substance the mites produce. Drying items in a hot dryer will kill the mites once the clothes are dry, but will not remove the allergic substance.
Unfortunately, most studies have failed to show improvements in asthma from using strategies or products to get rid of or reduce contact with house dust mite allergens. It is better to focus on gaining control of symptoms by using asthma medications correctly.
Tips to reduce exposure to pollen
The season for pollen allergies can last for several months and occurs when plants are flowering. The timing of your own personal allergy season will depend upon which plants you are allergic to, and when they flower.
A direct way to manage pollen allergies is to reduce your exposure to pollens. Pollen counts are published in the media and can help you to plan to avoid exposure.
To reduce your exposure to pollen:
- stay indoors in the morning, if possible – grass pollens mainly circulate in the morning
- avoid mowing the grass, or wear a mask when you mow – if someone else is doing the mowing, stay indoors while they do so
- keep windows closed in your home and car
- avoid picnics in parks or in the country during the pollen season
- wear sunglasses to protect your eyes
- plant a low-allergy garden (plants that are pollinated by birds or insects, not wind) around your home, especially near the windows of your home.
Tips to reduce exposure to mould spores
The best strategy for any allergy is to avoid the allergy trigger. For mould spores, this can be difficult, but you can certainly take action to reduce mould in your home.
To reduce mould in your home:
- treat existing mould on surfaces such as bathroom ceilings and walls
- remove carpet from bedrooms
- eliminate sources of dampness – leaking pipes or seeping groundwater
- change filters regularly in heating and air-conditioning units, and having heating ducts cleaned often
- ventilate bathrooms
- recycle old books and magazines.
Non-allergy triggers for asthma
Non-allergy triggers do not involve an allergic reaction of your immune system. Instead, non-allergic triggers act directly on your airways to lead to asthma symptoms.
Understanding what triggers your asthma symptoms will help you to manage them. Ask your doctor for tips on how to avoid or reduce exposure to situations that can trigger asthma.
Common non-allergy triggers of asthma symptoms
Non-allergy triggers that can lead to asthma symptoms include:
- exposure to cigarette smoke
- airway infections like colds and flu, especially during infancy
- indoor and outdoor air pollution
- weather conditions – such as cold air or thunderstorms
- food additives – such as sulphites in food and drink.
Tips to reduce exposure to cigarette smoke
Aim for a smoke-free environment, both for yourself and your children. If you smoke, speak to your doctor about quitting. If you are pregnant and you smoke, your child is at much greater risk of asthma. Babies of mothers who smoke are four times more likely to develop asthma.
Do not allow anyone to smoke in your home. Smoking in a small area like a car is especially bad and opening the windows does not help. Even if you do not smoke near your children, the smoke remains in your clothes and can still affect children.
Tips to reduce the risk of airway infections
Colds are a more common cause of asthma symptoms than flu (influenza). After an airway infection, people with asthma are more likely to develop complications, such as pneumonia or bronchitis.
To reduce the risk of an airway infection, such as colds or flu:
- have an annual flu vaccination
- avoid contact with others who have cold or flu symptoms
- avoid sharing personal items with someone who has cold or flu symptoms
- wash your hand regularly
- clean surfaces around your home regularly.
Tips to reduce exposure to indoor pollution
To reduce air pollution in your home:
- avoid all cigarette smoke in your home
- make sure all heaters and gas appliances are vented correctly and inspected every year
- avoid fan-forced ducted heating because it circulates dust – choose radiant heating instead
- avoid wood stoves or make sure the doors to the stove fit tightly
- avoid using open fireplaces
- avoid household products that can irritate the airways – such as cleaning products, paints, varnishes, pesticides, perfumes and soaps.
Tips to reduce exposure to outdoor pollution and weather
Avoiding outdoor pollution or weather conditions can be difficult, but tips for reducing your exposure include:
- checking newspapers and other media for daily outdoor air quality reports
- staying indoors with windows closed on smoggy and dusty days – use an air conditioner to filter the air
- staying indoors with windows closed and vents blocked if hazard-reduction burns or bushfire smoke is in your area
- avoiding physical activity on high-pollution days or if smoke is in the air
- avoiding cold air in winter – wear a scarf over your nose and mouth, and exercise indoors.
Tips to reduce the risk of exercise-induced asthma
Exercise is an important part of a healthy lifestyle and can help to control asthma symptoms. Many top athletes, including Olympic medallists, have asthma.
Tips to reduce the risk of asthma symptoms during exercise include:
- managing and controlling your asthma with preventer medication so you are less likely to have symptoms
- always carrying your reliever medication with you
- warming up as usual before exercising – your doctor may recommend taking reliever medication 15 minutes before exercising
- cooling down after exercising – asthma symptoms can appear up to 30 minutes after exercising.
- I symptoms appear, start asthma first aid [link to asthma first aid doc] and return to exercise only if you can breathe freely. If symptoms appear a second time, start asthma first aid and do not return to exercise. Visit your doctor for a review of your asthma symptoms.
Scuba diving and asthma
Scuba diving if you have asthma can be life-threatening. In fact, it is the only sport that is not recommended for people with asthma.
The risk is that you may breathe in air at a certain pressure at a certain depth, then have that higher pressure air become trapped in your lungs due to asthma closing the air passages in your lungs. As you rise to the surface (where the air pressure is lower), that trapped air will expand and can cause your lung to burst. This causes something known as barotrauma (as pneumothorax or air embolism), which is often fatal.
If you wish to scuba dive you will need lung function testing and medical clearance to do so. The Asthma Foundation Victoria recommends that people with asthma avoid scuba diving completely.
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