Asthma and allergies are closely related.  Did you know that up to 80% of people with asthma also have allergies and that most people with asthma have allergic asthma… 

So, what is asthma? 

Asthma occurs when a person’s sensitive airways become swollen, tight, and produce mucus, all of which result in a narrowing of the airways and difficulty breathing. Often the airways do this in response to breathing in an allergen (in the air).

What is an allergen? 

Substances that cause allergic reactions are called allergens.

Common allergens that cause allergic reactions include pollens, mould, dust mites, animal skin or fur, some foods, and some medicines. Not all substances which cause allergic reactions will cause asthma symptoms. The substances which commonly cause allergic asthma symptoms include pollen, dust mite, animal dander, and mould. Latex and dust can also cause asthma symptoms and this is commonly the case in occupational asthma, where exposure to the allergic substance in the workplace causes asthma.

Common allergic reactions include skin rash, itchiness, and less commonly nausea and vomiting. Severe allergic reactions can be life-threatening. Anaphylaxis is a life-threatening condition that describes a severe reaction to the allergen causing collapse and difficulty breathing.

It is extremely important to be clear about what allergies you have and how they can be managed.

In people with asthma, exposure to known allergens can worsen asthma symptoms and trigger flare-ups.

How do people with asthma control their allergic symptoms? 

Assessment and treatment of allergies is another part of good asthma management. It is recommended that you talk to your doctor about how often and how severe your allergic and asthma symptoms are and for you to work together, to identify which allergens could be affecting you. Your doctor might recommend allergy testing to confirm your type of allergens, which can be done with skin prick testing and blood tests, your doctor will decide if both or only one testing method is needed.

With a clearer picture of what you are allergic to, your doctor can discuss options for allergy management. This will help you avoid further exposure and reduce the likelihood of associated asthma symptoms and asthma flare-ups.

What will this mean? 

The best way to prevent allergic reactions and allergic asthma will be to avoid your known allergens/triggers completely. Some allergens/triggers will be quite difficult to avoid altogether but some can be eliminated and/or your exposure reduced. The general rule in avoiding allergens and asthma symptoms is to not only reduce exposure but to combine both efforts of maintaining good asthma control and also managing your allergies, as advised by your doctor. Single measures have rarely been shown to be effective at reducing exposure and its complications – causing allergies and asthma flare-ups.

View more information on the types of allergens/triggers here.

How to manage allergies and asthma? 

The best approach to managing asthma, in general, is through regular use of inhaled corticosteroid preventer medicines. These medicines work to reduce the sensitivity of the airways to triggers like allergens and reduce the swelling and mucus production which occurs when the airways are irritated. Effective preventer use is the importance of a personalised written Asthma Action Plan. The written Asthma Action Plan will serve to provide the person with asthma guidance, from their doctor on how to control their asthma on an ongoing basis and will include special instructions on what to do in case of worsening symptoms or how to prevent symptoms caused by known allergens.  

Hay Fever is an allergic condition usually caused by exposure to pollen or house dust mite and appears commonly as any of blocked or runny nose, frequent sneezing, itchiness in nose, throat, and eyes, cough, and eye-watering. There are many products available at the pharmacy to treat and control these symptoms and doing so has been reported to improve the feeling of asthma control. 

Like asthma treatment, the best treatment is the one which controls symptoms with the lowest dose: 

  • Preservative-free saline irrigation works by washing the allergens out of the nasal passages which can prevent or reduce the allergic response to these allergens 
  • Oral antihistamines may be preferred for short term use where intranasal treatments are not effective on their own or where symptoms are mild and infrequent 
  • As with asthma, it is important to have your hay fever reviewed and in case it doesn’t improve, referral to a specialist is recommended. 
  • Intranasal corticosteroids are used when necessary to reduce the inflammation caused by the allergic reaction and reduces symptoms. These are indicated where the hay fever symptoms are persistent or moderate to severe 
  • Intranasal decongestants and antihistamines can be effective short-term treatments of hay fever symptoms in addition to intranasal corticosteroids 

Avoiding exposure to and management of allergens can be difficult and careful consideration should be made around the specific allergies and the impact on your overall health including your asthma control. If asthma control is poor, in case of severe asthma or unstable asthma, people are encouraged to discuss specialist referral for allergy management with their GP. This might mean allergy testing to guide treatment decisions; a discussion around the possibility of accessing allergen desensitisation treatments called allergen immunotherapy; or perhaps specialist treatment for severe allergic asthma. 

Asthma Management

 Allergen Immunotherapy

Specific allergen immunotherapy is a targeted medical program involving gentle and gradual exposure to your trigger/s, called immunotherapy. The aim of this treatment is to desensitise the immune system to the known allergen so that it no longer overreacts to that allergen. Speak to your doctor for more information about immunotherapy or desensitisation. This may be an expensive treatment as it is currently not subsidised by the government.  Benefits can be experienced within months after starting treatment but the full course of treatment will usually be up to several years.  But it may be worth it, depending on how burdensome your symptoms are and the cumulative costs of current treatments.

Immunotherapy for asthma

Biologic Therapy

Severe allergic asthma treatment may involve regular injections of a new type of therapy called biologic therapy which aims to interrupt the immune system’s processes which lead to inflammation in the airways in response to allergens. This treatment is only available for patients whose asthma is poorly controlled despite using high doses of inhaled preventer treatment. 

If your asthma is difficult to control or frequently disrupted by exposure to allergens, we strongly recommend discussing the possibility of a referral to a specialist.

When hay fever or allergic asthma symptoms are especially problematic, we encourage you not to rest until you have them under control. Allergies can have a profound impact on your quality of life. 

Learn more about biologic therapy here.

Learn more about Allergen Immunotherapy here

Asthma Allergen Immunotherapy

Flo and Stallergenes Greer are campaign partners of Asthma Australia and have not been involved in the development of this webpage.


Reference: National Asthma Council Australia. Australian Asthma Handbook, Version 2.1. National Asthma Council Australia, Melbourne, 2020. Website. Available from: