What is grass allergy?

A grass allergy is when you experience symptoms after exposure to pollen from grass. Allergic rhinitis (hay fever) and thunderstorm asthma are conditions caused by pollen exposure.

Grass pollen spreads when it is blown by the wind. It can travel long distances. Australian native grasses are less likely to cause allergies than those introduced from overseas, such as exotic or lawn-variety grasses.

What are the symptoms of grass allergy?

If you have a grass allergy, you may experience symptoms of allergic rhinitis (hay fever) and thunderstorm asthma.

Symptoms of hay fever can include:

• runny or blocked nose
• sneezing
• itchy, watery or red eyes
• throat irritation
• snoring

Symptoms may range from mild to severe.

Thunderstorm asthma occurs when a thunderstorm the spread of large amounts of pollen in the air. This can trigger asthma symptoms in people with asthma who are allergic to pollen. Symptoms may include:

• coughing
• chest tightness
• wheezing
• shortness of breath

What causes grass allergy?

Grass allergy is when your immune system reacts following exposure to grass pollens, leading to conditions including hay fever and thunderstorm asthma.

When am I at risk of grass allergy?

You are more likely to experience symptoms of grass allergy during times of year when grasses are producing more pollen.

Different parts of Australia have different grass allergy seasons. You might have symptoms during different parts of the year, depending where you live.

In northern coastal areas, grass allergy season is around January, February and March. In southern Australia, it’s generally around October, November and December.

There is more grass pollen in inland areas. There is also more pollen on Australia’s south coast than the east coast.

It can be hard to completely avoid exposure to pollen, and some pollen seasons can last for months.

To find out when you might be at risk from certain types of pollen, check the ASCIA pollen calendar.

When should I see my doctor?

If you have a history of asthma and have symptoms of hay fever or thunderstorm asthma, you should see your doctor to review your asthma management plan. This is because grass allergy can make asthma worse.

If you do not have asthma, but experience wheezing in the spring and summer months, you should also see your doctor.

You are also recommended to see your doctor if you feel that symptoms of grass allergy are affecting your general health and quality of life.

Read about how to get the most out of your doctor’s appointment.

How is grass allergy diagnosed?

Your doctor can diagnose grass allergy by:

• asking you about your symptoms, any patterns or triggers and if they go away when you are on holiday
• examining your nose and eyes
• referring you for allergy testing

You find it helpful to keep a diary of your symptoms to discuss with your doctor.

Your doctor may also refer you to a specialist allergy doctor.

How is grass allergy treated?

Your doctor may first recommend medicines to improve your hay fever symptoms. If you have severe hay fever and your symptoms do not improve with medicines, your doctor may refer you for immunotherapy treatment.

Immunotherapy must be a doctor specialising in allergies. During immunotherapy, you will be exposed to small but increasing doses of allergens over a long period of time to help your body learn to tolerate the allergen without reacting to it. Treatment usually starts to work within a few months, but needs to be continued for up to 5 years.

How is hay fever treated?

Your doctor or pharmacist may recommend medicines to relieve your hay fever symptoms, such as:

• Antihistamines (tablets, eye drops or nasal sprays) to help stop mild symptoms such as sneezing and itchy eyes.
• Corticosteroid nasal sprays to reduce inflammation. They can be very effective but you need to use these regularly.
• Decongestants (nasal sprays or tablets) relieve a blocked nose, but can cause side effects such as tremors, sleeping problems, anxiety and increased blood pressure. They should not be used for long periods.
• Salt water nasal sprays can relieve a blocked nose.

It is important that you follow your doctor’s or pharmacist’s instructions. Sometimes you may need to take more than one of these medicines to manage your symptoms. Most of these medicines are over-the-counter medicines and are available without a prescription.

How is thunderstorm asthma treated?

If you experience thunderstorm asthma, your doctor may recommend taking asthma medicine as a precaution in spring, when you first notice coughing or wheezing.

It is important that you have an updated asthma action plan.

What are the complications of grass allergy?

Untreated, grass allergy can lead to:

• recurrent sinusitis or ear infections
• poor sleep and fatigue during the day
• headaches
• difficulty concentrating
• asthma that is harder to control

Can grass allergy be prevented?

Grass allergy can’t be prevented, but reducing exposure to pollen can help reduce your symptoms.

• Stay indoors when you can, especially when the pollen counts are high or when it is windy.
• Wear protective glasses (or sunglasses) to shield your eyes when you are outside.
• Try to avoid mowing your lawn. Stay inside while it’s being mown. If you cannot avoid mowing your lawn, consider wearing a mask and take an antihistamine that does not make your drowsy.
• Keep your windows closed at home and in the car.
• If you use air conditioning in the car, put it on the recirculate setting.
• Dry your bedding and clothing indoors or in a dryer.
• Have a shower when you get home to wash off pollen residue from outside.

Here are some tips to try to prevent thunderstorm asthma:

• Stay inside just before, during and after thunderstorms and on days with high pollen counts.
• Use your asthma preventer medicines every day, especially when pollen counts are high or thunderstorms are predicted.

Resources and support

• Learn more about thunderstorm asthma at Australian Society of Clinical Immunology and Allergy (ASCIA).
• Visit Allergy and Anaphylaxis to read all about allergic rhinitis.
• Call the healthdirect helpline on 1800 022 222 at any time to speak to a registered nurse (known as NURSE-ON-CALL in Victoria) for more information and advice.

Aboriginal and/or Torres Strait Islanders

Download ‘Lung health for kids’, an app for Aboriginal and/or Torres Strait Islander children and families that will teach you about some common lung conditions.

Other languages

Visit The Victorian Government Department of Health for resources in many languages about thunderstorm asthma.