Pollen Allergy

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Pollen from grasses, weeds or trees can trigger symptoms of allergic rhinitis (hay fever), and asthma. Pollen seasons can last for several months and exposure is difficult to avoid. However, there are several ways to prevent or reduce pollen allergy symptoms.

What is pollen?

The word pollen is derived from the Greek word meaning 'fine flour' and the role of the pollen grain is to fertilise the female flower to reproduce plant species.

Pollen grains can be spread by birds, insects (bees, butterflies and moths), andwind:

Most of the pollens that cause allergies are produced by airborne pollen from northern hemisphere grasses, trees and weeds:

Several types of weeds with highly allergenic pollen have been introduced to Australasia, including:

Pollen allergy causes allergic rhinitis

The correct name for hay fever is seasonal allergic rhinitis. Symptoms are caused by the body's immune response to inhaled pollen, resulting in chronic inflammation of the eyes and nasal passages.

Allergic rhinitis symptoms include:

Allergic rhinitis is a common and debilitating disease

Pollen can trigger asthma

Pollen can directly trigger asthma and allergic rhinitis. Small particles of allergens can penetrate deep into the airways of the lung. Thunderstorms can also contribute to this:

Pollen seasons can last for months

In Australia pollen numbers are lower on the east coast where most winds come from the sea, and where there is protection from westerly winds by the Great Dividing Range. Pollen numbers are higher on the Victorian south coast because most winds are from the north carrying pollen from the northerly grasslands. In South Australia and Western Australia, the amount of pollen can vary according to the wind.

Pollination times vary with the plant variety and its location.

The principal grasses growing in the northern coastal areas are subtropical and mainly flower in January, February and March. Allergenic grasses in the southern part of Australia are mostly Northern hemisphere grasses, with the main flowering period from October to December.

Diagnosis is important

A history should be taken of the timing of symptoms, identifying plants and trees that grow in the area, and if relief comes by going away on holiday. When the person's allergy history has been obtained, skin prick tests and/or blood allergen specific IgE tests, should be done using allergens that are in the area of their home and work. Test results can be interpreted by a doctor trained in allergy, in conjunction with the person's history.

Tips for reducing pollen exposure

Effective treatments are available

Seek advice from your pharmacist or doctor about medications that will relieve your symptoms. Although medications do not cure allergies, they are much more effective with few side effects. It is important to use them correctly, and to avoid medications that can cause problems such as frequent decongestant (unblocking) nose sprays or tablets.

Antihistamine tablets or syrups (non-sedating) help to reduce symptoms (sneezing, itchy and irritated eyes), but they are not as effective in controlling severe nasal blockage and dribble. The advantage of antihistamines is their flexibility; you can take them when you have symptoms, and avoid them when you are well. Antihistamine eye drops can also be helpful in controlling watery eyes due to allergies.

Intranasal corticosteroid nasal sprays (INCS) have a potent action on inflammation when used regularly (like asthma preventer medications). These need to be used regularly and with careful attention to the way in which they are used. Different brands of INCS vary in strength and effectiveness, so it is important to read the labels and check details with your pharmacist or doctor.

Combination medications containing an antihistamine and intranasal corticosteroid nasal spray are available and offer the combined advantages of both medications.

Decongestant sprays unblock and dry the nose, but should not be used for more than a few days as they can cause long term problems in the nose

Decongestant tablets unblock and dry the nose, but should be used with caution as they can have 'stimulant' side effects like tremors, trouble sleeping, anxiety or an increase in blood pressure. People with high blood pressure should not take decongestant sprays.

Natural products such as salt water nasal sprays or douches can be effective in relieving symptoms.

Appropriate management of pollen asthma includes commencing asthma preventer medication before, or at the first sign of asthma symptoms. Some people undergoing allergen immunotherapy for allergic rhinitis find that their asthma improves as well.

Allergen immunotherapy is a long-term treatment option

Medications only reduce the severity of symptoms and do not cure allergic rhinitis. Another treatment option is allergen immunotherapy (AIT) which is also known as desensitisation. AIT switches off the allergic reaction, by repeatedly introducing small doses of allergen extracts, by injection, sublingual tablets, sprays or drops.

AIT is a long term treatment which is usually given over a few years.

It should only be started after assessment by a clinical immunology/allergy specialist to determine if this is a suitable treatment option.


© 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

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Updated May 2019