This leaflet has been written to provide information about your challenge test. We hope it answers some of the questions or concerns you may have. It is not intended to replace talking with medical or clinical staff.

What is a Mannitol Challenge Test?

Mannitol is a naturally occurring sugar which when inhaled in small doses under controlled conditions mimics the body’s response to an allergen. It produces a change in the fluid balance of your airways which causes a response from your airways. A classic example of this is hay fever. In people with active asthma there is an enhanced reaction to mannitol within the airways.

Why am I having this test?

You have probably been asked to undergo this test to confirm or rule out a diagnosis of asthma. Asthma can be difficult to diagnose with basic lung function tests. This test is specific in identifying individuals with asthma.

How long will the test take?

Please allow 45 – 60 minutes for your appointment.

What does the test involve?

The procedure will be explained to you in detail on the day of the test. We will check you are happy to proceed with the test. You will be asked to inhale increasing amounts of mannitol through a small inhaler device. The response of your airways will be measured after each dose by asking you to perform a breathing test. For this you will breathe in as deeply as possible and then blow out as quickly as you can into a machine through a disposable mouthpiece and with your nose sealed with a nose clip.

If your airways respond to the mannitol we will give you some of the bronchodilator medication Salbutamol to ensure your airways open back up and return to normal before you leave our department.

How should I prepare for my test?

Before attending for your challenge test, please:

• Do not take vigorous exercise for 30 minutes
• Do not wear any tight clothing that may restrict your breathing
• Do not smoke for at least 1 hour
• Do not eat a heavy meal for 2 hours
• Do not take alcohol for 4 hours
• Withhold medications as demonstrated in the table overleaf

Medication withholding times

As this test is for asthma, we want to see the reactivity of your airways. We therefore ask you not to use specific medications or inhalers prior to the test as they may interfere with the results. Please use the table below to see which medications should be withheld, and for how long. Please continue to take all other prescribed medication as normal.

If you are short of breath or struggling and do take any of these medications or inhalers prior to the test, please contact the Pulmonary Function Department as we may not be able to do the test. If necessary we will rearrange your appointment.

If you have any queries regarding which medication you should or should not take, please contact the Pulmonary Function Department directly. The telephone number for the department is on your appointment letter.

Results

Please note that you will not be given the results on the day of your test. The results will be sent to the consultant who referred you for the test who will discuss them with you when you next attend clinic.

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