Asthma diagnosis - Lung Function Test

Asthma is characterized by reversible airway obstruction. That means the airway narrowing in asthmatic patients should be, at least at the outset, fully reversible. As the disease progresses without treatment, airway remodeling occurs and this leads to irreversible loss of lung function.

Patients with asthma often present with chest tightness, shortness of breath and wheezing. However, chronic cough is an early sign of asthma, and many patients might not experience wheezing. It is now recognized that asthma patients should receive treatment early on in order to prevent irreversible loss of lung function, especially in children. It is therefore important to make a diagnosis early so that treatment can be started.

Lung Function testing is an essential tool in asthma management. At the Centre for Allergy and Asthma Care, we employ the KoKo Spirometer for lung function testing. All asthmatic patients should undergo spirometry testing at baseline and periodically during treatment to monitor their progress.

Some patients with asthma and chronic cough rarely develop wheezing and airway narrowing. Regular spirometry testing will therefore be normal. For these patients, inhalation challenge with methacholine will show bronchial hypersensitivity. We employ the KoKo DigiDoser to perform inhalation challenge. This computer-controlled dosimeter can accurately administer dosages for inhalation followed by spirometry measurements. We also perform lysine-aspirin inhalation challenge to diagnose aspirin-sensitive asthma, and allergen challenge in special circumstances such as occupational asthma.

Reference information:  www.allergy.hk

The information aims to provide educational purpose only. Anyone reading it should consult physician before considering treatment and should not rely on the information above.