Individual research recommendation details

Recommendation ID

NG80/2

Question

Diagnosing asthma in adults (aged 17 and over):- What is the clinical and cost effectiveness of using an indirect bronchial challenge test with mannitol to diagnose asthma in adults (aged 17 and over)?

Any explanatory notes
(if applicable)

Why this is important:- Chronic airway inflammation is associated with bronchial hyper-responsiveness, which is integral to defining asthma. Bronchial challenge testing can help diagnose asthma and assess response to inhaled corticosteroid therapy. It can also be used to monitor asthma control, alongside assessing
symptoms and lung function. It is increasingly used in asthma management, although currently most tests are performed only in specialised centres or research settings.
Indirect challenge tests with inhaled mannitol act via active inflammatory cells and mediators, whereas direct challenge tests with inhaled histamine or methacholine act directly on bronchial smooth muscle. Indirect challenge testing is more specific but less sensitive than direct challenges.
Direct challenge testing may not identify a person whose asthma will respond to inhaled corticosteroids. A positive result to an indirect challenge may reflect active airway inflammation that is likely to respond to inhaled corticosteroid therapy. Because a response to mannitol indicates active airway inflammation, identifying non-responsiveness in treated patients may help demonstrate good asthma control with inhaled corticosteroid therapy and identify people whose asthma is less likely to deteriorate after a dose reduction.
Mannitol bronchial challenge testing is quicker and simpler than current direct tests (which are generally confined to specialist respiratory centres), and uses a standardised inhaler device, so is potentially more useful in primary care.

Source guidance details

Comes from guidance

Asthma: diagnosis, monitoring and chronic asthma management

Number

NG80

Date issued

November 2017

Other details