Allergen Minimisation

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Allergies are very common in Australia and New Zealand, affecting around 20% of people at some time in their lives. Allergy is also one of the major factors associated with the cause and persistence of conditions such as allergic rhinitis, eczema and asthma. Identifying the allergen/s causing the symptoms is an essential part of treating allergic diseases.

In some cases the offending allergen may be obvious. However, in other cases your doctor will need to consider your medical history together with the results of allergy tests (skin prick tests or allergen specific IgE blood tests), which may require referral to a clinical immunology/allergy specialist.

Once the allergens are correctly identified, the following practical advice on avoiding or minimising your exposure to known allergens may help.

House dust mites are common allergens in Australia and New Zealand

House dust mites are the most common allergen source in humid areas such as coastal cities and towns. Levels tend to be lower in drier inland areas. There is no easy way of removing house dust mites. Regardless of what advertisements may say, there is no vacuum cleaner, dust mite spray or dry cleaning that will completely eliminate dust mites.

Depending on the severity of symptoms, and in the case of childhood asthma, eczema, chronic or recurrent sinusitis, and middle ear infections with dust mite as a provoking trigger, the following advice may help.

House dust mite minimisation

The first room to tackle is the bedroom and in particular the bedding, where we spend the greatest number of consecutive hours. A combination of the following four measures is recommended:

The following advice can apply to bedrooms as well as other rooms in the house:

Pet dander minimisation

Exposure to pets (such as cats, dogs, guinea pigs, horses, rabbits, mice, rats) at home or work can trigger allergic reactions in some people.

Cats and dogs are a major source of allergens in the home environment. The allergens come from the sweat glands in all cats and salivary glands in all dogs. Although the amount of allergen released can vary between breeds, there are no hypoallergenic animals or breeds.

As allergens are stuck to the hair and skin of pets, the allergens become airborne when the pet sheds their hair. The allergens can remain airborne for some time. Cat allergen is especially difficult to remove from homes. It can remain in the house for months after the cat has been removed. Cat allergen can also be found in places where cats have never lived. For example, it can be carried around on clothing to schools and offices.

The most effective method of allergen avoidance for people who are allergic to pets is removal of the pets from the home. For example, if there is no doubt that cat or other animal allergen is a major cause of symptoms then the best advice is for the animal to be removed from the home. It can be an emotional decision, but removing the pet should be considered.

If pets cause only minor problems, keeping pets out of bedrooms and living areas may be a compromise. Even then, it may take months after pet removal before allergen levels are reduced. The effectiveness of some measures such as washing animals frequently and using HEPA air filters remains uncertain.

Dogs, guinea pigs, mice and rabbits are not as allergenic as cats and are more easily kept outside, but can still cause annoying and occasionally serious problems. Horse allergy is very serious and even animal hair on clothes may be sufficient to trigger asthma. Great care must be taken to shower and change clothes before returning to a home of a person allergic to horses. Birds may occasionally cause allergic symptoms. This is a different problem to pigeon fancier's lung which is a serious condition and requires complete avoidance.

Mould minimisation

Mould in the home can show as mould, mildew or a musty smell. It is commonly found in bathrooms, refrigerators and in places with little air circulation such as walk-in and built-in wardrobes, and in bedrooms with ensuite bathrooms.

If you are allergic to mould, you may consider:

Pollen minimisation

In Australia and New Zealand the height of the grass pollen season usually occurs between late September and December, and the major amount of pollen in the air usually occurs between 6am and noon. Depending on the weather patterns, there may be an increase of pollen in the early hours of the morning.

Although pollen is known to be blown long distances on windy days, most pollen is deposited within a short distance of its source. The highest pollen counts occur on calm, hot, sunny days in late October, November and December, although in Queensland the season is different, and January is a particularly high pollen count month. Pollen allergy in tropical areas mainly occurs during the dry season. However, higher pollen counts are also associated with thunderstorms.

When pollen granules come into contact with water, starch granules are released that are small enough to be breathed into the airways, triggering allergic rhinitis (hay fever) and asthma in some people.

Avoidance of pollen is difficult but the following advice may help:

Seek advice from your doctor or pharmacist about medications or treatments that will relieve your symptoms.

Information about pollen counts in Australia is available at www.pollenforecast.com.au 

 

© ASCIA 2019

ASCIA is the peak professional body of clinical immunology/allergy specialists in Australia and New Zealand.

ASCIA resources are based on published literature and expert review, however, they are not intended to replace medical advice. The content of ASCIA resources is not influenced by any commercial organisations.

For more information go to www.allergy.org.au

To donate to immunology/allergy research go to www.allergyimmunology.org.au

Updated March 2019