5th January 2024

Diagnostic criteria in symptomatic patients

Patients aged 17 years and above

Diagnose asthma in the following conditions:

• FeNO level of 40 ppb or above with either positive BDR, positive peak flow variability, or bronchial hyperactivity.
• FeNO level between 25-39 ppb and positive bronchial challenge test
• Positive BDR and peak flow variability (irrespective of FeNO level)

Patients aged between 5 and 16 years

Diagnose asthma in the following conditions:

• FeNO level of 35 ppb or more with peak flow variability
• Obstructive spirometry with positive BDR

Children under the age of five

Clinical judgment should be based on any positive objective test and signs and symptoms.

Adapted from: Recommendations | Asthma: diagnosis, monitoring and chronic asthma management | Guidance | NICE [Internet]. Nice.org.uk. NICE; 2017. Available from: https://www.nice.org.uk/guidance/ng80/chapter/Recommendations#diagnostic-summary

References 

• Asthma: When should I suspect asthma? [Internet]. NICE. 2021. Available from: https://cks.nice.org.uk/topics/asthma/diagnosis/diagnosis/
• Recommendations | Asthma: diagnosis, monitoring and chronic asthma management | Guidance | NICE [Internet]. Nice.org.uk. NICE; 2017. Available from: https://www.nice.org.uk/guidance/ng80/chapter/Recommendations#pharmacological-treatment-pathway-for-adults-aged-17-and-over