What is Asthma?
Asthma is a common chronic respiratory condition characterised by inflammation of the lower airways.
- Most people with asthma have Type 2 (T2) inflammation
- T2 inflammation may be associated with eosinophils in the blood or airways
- Identifying T2 severe asthma helps doctors tailor and monitor treatment effectively
Laboratory Testing for Asthma
Routine tests and T2 inflammation biomarkers help guide treatment decisions. These include:
Full Blood Count (FBC) with Differential Count
- Confirms or excludes eosinophils in the blood
- The eosinophil count helps assess treatment response
Sputum Eosinophils
- The presence of eosinophils in sputum despite corticosteroid treatment suggests more severe asthma symptoms
Total Serum IgE
- Helps guide asthma-specific treatment plans
Specific IgE Testing
- Identifies allergens that could trigger asthma symptoms
- Supports allergen avoidance strategies
Fractional Exhaled Nitric Oxide (FeNO)
- A quick, non-invasive test to monitor airway inflammation
- Helps guide the doctor’s decisions about asthma treatment and medication adjustment
What is the FeNO Test?
- Performed using a handheld device
- Involves a simple inhale and exhale process
- Result is available instantly
- You will receive a personal mouthpiece for the test
- Useful for:
- Monitoring inflammation
- Adjusting medication
- Identifying patients who may benefit from anti-inflammatory treatment
When is Asthma Considered Severe?
Your asthma may be classified as severe if symptom control is only achieved by:
- High-dose inhaled corticosteroids (ICS)
- A second controller medication and/or frequent use of oral corticosteroids
- If asthma remains uncontrolled despite these interventions
Preparing for a FeNO Test
The FeNO test can be done immediately, but for most accurate results, follow this preparation schedule:
1 Hour Before the Test:
- Do not eat or drink
- Avoid smoking
- Do not exercise
12 Hours Before the Test:
- Avoid smoking
- Avoid eating high-nitrate foods, such as:
- Rocket
- Turnip
- Carrot
- Spinach
- Cabbage
- Potato
- Lettuce
- Green beans
- Garlic
- Radish
- Leek
- Sweet pepper
- Beetroot
- Spring onion
- Green pepper
- Chinese cabbage
- Cucumber
24 Hours Before the Test:
- Avoid alcohol consumption
Preferably, book the test for the following day to allow for proper preparation.