Bronchial challenge tests

A bronchial challenge test measures how sensitive your airways are. It’s used to help diagnose asthma.

What is a bronchial challenge test?

A bronchial challenge test can also be called an airway provocation test or direct challenge test.

It involves breathing in a powder or mist that can irritate the airways and make them get narrower like how an asthma trigger would irritate the airways.  

The test will find out how sensitive your airways are. People with sensitive airways will be affected by a much lower dose of the powder or mist than people with healthy airways.

The test is done carefully in a hospital to make sure it’s safe. It is not usually recommended for children. Guidelines recommend them for people aged 17 and over.

When will I need a bronchial challenge test?

A bronchial challenge test is used to see how sensitive your airways are. This can help your healthcare professional to understand if you have asthma. This test is normally done if other tests, such as spirometry and FeNO, haven’t given a clear result, but you still have unexplained symptoms.

Bronchial challenge tests are not used to monitor asthma once you have an asthma diagnosis. 

How can I prepare for a bronchial challenge test?

You might get a leaflet or some instructions with your appointment letter. It’s important that you read this carefully, as it will help you to prepare for the test.

You may be asked to:  

  • stop taking inhalers 12 hours before your test
  • stop taking antihistamines 12 hours before your test
  • stop smoking for six hours before your test
  • stop drinking caffeine for six hours before your test
  • avoid intense exercise six hours before your test. 

How is the test done?

A bronchial challenge test is done in a hospital. But you won’t need to stay overnight. The test usually takes up to 90 minutes.

Before the test begins, you will be asked to do some other simple breathing tests, including spirometry. This is to check your lung function. If the results are okay, then you can do the bronchial challenge test.

You’ll be asked to breathe in a medication through a hand-held device or a nebuliser. This will cause a reaction in your airways. The medication starts at a very low dose and builds up slowly.

Your breathing will be tested between each dose with spirometry. This is to check if there are any changes in your airways.  

Don’t worry – if any symptoms are triggered from the test, your specialist will be there to reassure, monitor, and treat you with a reliever medicine if necessary. 

What do my test results mean?

If your breathing gets worse quickly during the test, this may mean your airways are more sensitive. This could mean you have asthma. Your doctor will discuss your results with you and tell you if you need asthma treatments.

If you don’t have a reaction to the powder or mist you breathe in, it’s less likely that you have asthma.

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