What is an allergy?
An allergy occurs when the body’s immune system over-reacts to a normally harmless substance, which could be in the air, water or things we touch or eat. A substance that triggers an allergic reaction is called an allergen.
When a person with an allergy comes into contact with an allergen, their immune system products a type of antibody called IgE (Immunoglobulin E). This antibody then releases chemicals within the body, including histamine, which causes allergy symptoms like sneezing, coughing, wheezing and itchiness.
How are asthma and allergies connected?
Asthma and allergies are closely related, but experts do not yet fully understand how this relationship works. It’s estimated that up to 80% of people with asthma also have allergies, and many people with asthma have allergic asthma.
What is allergic asthma?
For some people, when their immune system responds to an allergen, they experience asthma symptoms. This is known as allergic asthma. People with allergic asthma may also require treatment for their allergies in addition to any asthma treatment.
Allergic rhinitis (hay fever) is an extremely common asthma trigger. It can also exacerbate asthma and make diagnosing asthma more difficult. Hay fever and asthma both affect the airways, with hay fever symptoms commonly experienced in the upper airways (nose, mouth, throat) and asthma symptoms experienced in the lower airways (windpipe, lungs). Treating symptoms in both your upper and lower airways will help control both allergies and asthma.
What are the most common allergens for people with asthma?
In New Zealand, the most common asthma-producing allergens are house dust mites, animals, pollen, mould and fungal spores.
How do I find out what I am allergic to?
A skin prick test or a RAST test administered by an experienced doctor or allergy specialist can help determine which substance or substances are triggers. Talk to your doctor if you would like to organise an allergy test.
How do I treat asthma and allergies?
Your doctor will be able to advise you on the best treatments for both your asthma and allergies. They may prescribe antihistamine tablets or corticosteroid (anti-inflammatory) nasal sprays to treat your allergies.
If you know what you react to you may be able to improve your symptoms by reducing your exposure to allergens, which can be difficult. If pollen is a problem, then you might need to close windows and doors during spring or other times when pollen is plentiful. If pet hair is the issue, then consider keeping your pet outside or at least banning it from bedrooms.
Dust mites can be reduced with regular cleaning. Washing bedding in water hotter than 55C will kill dust mites. Wearing a face mask can help protect you from allergens when dusting or vacuuming. However, it isn’t possible to avoid exposure completely and so many people will need to use medicines as well to help their symptoms.