the Australian Dental Association
Written by the Australian Dental Association, Apr 01, 2023
Fact Checked

One in nine Australians have asthma - this is about 2.7 million people. People with asthma may be at higher risk of tooth decay, tooth erosion, gum disease and oral thrush. This increased risk is mainly associated with having a dry mouth due to a decrease in the amount of saliva within the mouth. A dry mouth can be caused by an increase in mouth breathing, rather than breathing through the nose, and/or as a side-effect of medications used to treat asthma.

Oral thrush

Oral thrush is a fungal infection that can occur in and around the mouth and throat. It is also known as oral candidiasis, and is mostly caused by an overgrowth of fungal yeast called candida albicans.

For people with asthma, oral thrush can be associated with the use of corticosteroid inhalers. In particular among patients that take high doses regularly from their inhaler.

Symptoms of oral thrush can include white patches of plaque on soft tissues in the mouth, such as the tongue, that can often be wiped off, leaving behind red areas that may bleed slightly.

Beta-2 agonist inhalers that are used to treat asthma symptoms have been shown to affect the amount of saliva that is produced causing a decrease in saliva in the mouth. Less saliva in the mouth can cause a dry mouth. This can be associated with higher amounts of oral candida which cause oral thrush.  

Ways to prevent oral thrush associated with asthma.

  • After using an asthma inhaler, rinse your mouth with water or fluoridated mouthwash. 
  • Use of a spacer device.
  • Increase the amount of saliva in the mouth.
  • Stay hydrated by drinking water.
  • Chew sugar-free chewing gum to help stimulate saliva flow.
Oral thrush does need to be diagnosed via a swab sample from inside your mouth. The swab is sent to a laboratory to be examined under a microscope to confirm the diagnosis.

Tooth erosion

The beta-2 agonist and inhaler medications used to manage asthma can cause a decrease in saliva production and flow into the mouth. As well they cause the dental plaque which is the soft sticky coat of bacteria found on teeth, to become acidic. These factors increase the risk of developing tooth decay or tooth erosion.

As well, people with asthma may also more commonly experience gastroesophageal reflux which can contribute to dental erosion.

Protecting your mouth

It is important to be using the correct technique when using an inhaler to manage your asthma. This can help to minimise side effects within the mouth.

Using a spacer with your inhaler helps to deliver the medication directly into the lungs. Less medication is deposited on the surface of the teeth, and soft tissues of the mouth and throat.

After using an inhaler, you should not brush your teeth immediately as the tooth enamel may be weakened from the acidic pH of the inhaler. Applying pressure to the teeth with a toothbrush at this time can lead to greater tooth wear over time. During this time while waiting to brush, try rinsing with water or fluoridated mouthwash. After teeth are exposed to very acidic sources, it is best to wait at least 60 minutes before brushing.

See your dentist regularly. Be sure to let them know if you have asthma or use medications for prevention or treatment.