Eric is 31 and suffers from chronic rhinitis and seasonal allergies during spring and midsummer.
Eric uses antihistamines for his seasonal allergies, but recently experienced breathing problems while jogging.
• Physical examination is normal
• The FENO value is 75 ppb
• Spirometry is normal
• What does the examination, especially the FENO value, tell you?
The FENO value strongly suggests an ongoing eosinophilic inflammation, which should respond to steroid treatment.
Action
Eric was prescribed 500 μg of ICS twice daily.
Visit 2
One month later the FENO value has fallen to 30 ppb and he has no symptoms.
Interpretation
This shows that he responded well to steroid treatment.
Conclusion
The FENO value helped the doctor to make an informed decision about prescribing ICS to Eric. A high FENO value in a steroid naive patient with unspecific airway symptoms strongly suggests the patient will respond to ICS, which was confirmed at the follow up visit when both symptoms and the FENO value had improved.