Spirometry is the Most Appropriate Next Investigation
For this child with recurrent wheezing, cough following URTI, and a history of eczema (a strong atopic marker), spirometry should be performed as the first-line objective test to evaluate for asthma. 1
Rationale for Spirometry
The European Respiratory Society strongly recommends against diagnosing asthma based on symptoms alone, even when classic features like recurrent wheeze and atopy are present 1
Spirometry is recommended as the first-line objective test for children aged 5-16 years under investigation for asthma, and most children in this age range can perform acceptable spirometry 1, 2
This child has key clinical features suggesting asthma: recurrent wheezing episodes, atopic history (eczema), and viral-triggered symptoms 3, 4
Why This Child Needs Objective Testing
Recurrent wheeze is the most important symptom of asthma, not isolated cough, and this child has documented wheezing on examination 1, 5
The presence of eczema plus wheezing places a child at high risk for persistent asthma throughout childhood 4
The European Respiratory Society guidelines emphasize that asthma diagnosis requires at least two abnormal objective tests, not just clinical suspicion 1
The Diagnostic Algorithm
First-line testing should include: 1
- Spirometry (looking for obstructive pattern: FEV1/FVC ratio below lower limit of normal)
- Bronchodilator reversibility (BDR) testing (≥12% improvement in FEV1 after bronchodilator)
- Fractional exhaled nitric oxide (FeNO) (elevated levels suggest eosinophilic airway inflammation)
Asthma should only be diagnosed when two or more of these tests are abnormal 1
Important Clinical Caveats
Spirometry is frequently normal in patients with asthma during stable disease, so testing is most useful when the child is symptomatic or when wheezing is present 1
If spirometry is normal but clinical suspicion remains high, consider watchful waiting with repeat spirometry during symptomatic periods or proceed to bronchial challenge testing 1
Children with chronic cough (>4 weeks) as the only symptom are unlikely to have asthma and should be investigated according to chronic cough guidelines, but this child has wheezing, not isolated cough 1, 5
What NOT to Do
Do not start a trial of asthma medication without objective testing first - the European Respiratory Society conditionally recommends against using symptom improvement after preventer medication to diagnose asthma 1
Do not rely on the history of eczema and wheezing alone to make the diagnosis, despite the strong atopic phenotype 1
Avoid assuming this is simple viral-induced wheeze without proper evaluation, as the recurrent nature and atopic background warrant formal assessment 3
Age Considerations
If this child is under 5 years old, spirometry may not be feasible, and the diagnostic approach differs significantly - in that case, a careful therapeutic trial with close monitoring may be appropriate, but the guidelines specifically address children aged 5-16 years for spirometry-based diagnosis 1