Asthma is a chronic inflammatory disorder of the airways characterised by variable and recurring respiratory symptoms, airflow limitation or obstruction and bronchial hyperresponsiveness.
Many diseases present with symptoms similar to those associated with asthma. If doctors are able to confirm inflammation of the airways, this allows them to rule out other conditions and confirm an asthma diagnosis.
A revolutionary new diagnostic tool, fractional exhaled nitric oxide (FeNO) testing involves the patient breathing into a hand-held machine used to measure the levels of nitric oxide in their breath.
During inflammation, the levels of nitric oxide (NO) release from the epithelial cells of the bronchial wall are higher than normal. The concentration of nitric oxide in exhaled breath is also known as fractional exhaled nitric oxide (FeNO) and can help to identify airway inflammation. A high level of nitric oxide can be a sign that the airways are inflamed.
In addition, if a patient has been diagnosed with asthma and the use of a preventative inhaler is not stopping symptoms, FeNO testing can be done to confirm whether the form of asthma is allergic or non-allergic.
Traditional methods of asthma assessment may be unreliable due to the nature of the tests as they are dependent on the efforts of the patient, and symptom assessments are subjective.
FeNO testing will provide physicians a better diagnostic tool for respiratory symptoms when there is no diagnosis of asthma. It will also allow for the appropriate prescription of anti-inflammatory medication (corticosteroids).
Consultant respiratory physician