Introduction

A bronchial challenge test is used to help determine how sensitive your airways are, and will help to confirm or refute a diagnosis of asthma.

Other Terms

A bronchial challenge test is also known as an:

• Airway provocation test; or
• Direct challenge test.

What is the Test For?

The test is used to confirm or refute a diagnosis of asthma.

Simply put, it is used to see how sensitive your airways are.

What Does the Test Involve?

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.

What is the Test Not Used For?

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

Who Can Have the Test?

It is not usually recommended for anyone aged 16 or under.

This test is normally performed if other tests, such as spirometry and FeNO (exhaled nitric oxide test), have not given a clear result, but you still have unexplained symptoms.

Where is the Test Performed?

The test is usually performed in a hospital setting.

In the military setting, the QE Hospital Birmingham (QEBM)/Royal Centre for Defence Medicine (RCDM) will conduct the test, although tests can occasionally be funded privately by the military within a private sector provider.

The test is not performed in Defence Primary Health Care (DPHC), and Defence Medical Services facilities (other than above) do not perform the test.

Joint Healthcare Group (JHG) respiratory consultants, working within NHS Trusts, perform the test to confirm/refute a diagnosis of Asthma. Service personnel are referred for this service from Primary Care to NHS hospitals when it is occupationally necessary to make the diagnosis.

How is the Test Performed?

• The test is performed in a hospital setting, will not require an overnight stay, and 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 will 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.
• If any symptoms are triggered from the test, the doctor will be there to reassure, monitor, and treat you with a reliever medicine if necessary.

What do the 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. The doctor will discuss your results with you and tell you if you need asthma treatments.

If you do not have a reaction to the powder or mist you breathe in, it is less likely that you have asthma.

Joining the Military

As part of your pre-service medical assessment, the doctor will specifically ask you about any asthma symptoms you may have.

Pre-Service

JSP 950 – Joint Service Manual of Medical Fitness (currently v3.0, August 2024) Annex D (p.4-D-2 to 4-D-3) discusses asthma, including medical standards.

In-Service

JSP 950 – Joint Service Manual of Medical Fitness (currently v3.0, August 2024) Annex D (p.5-D-1 to 5-D-2) discusses asthma, including medical standards.