Asthma Diagnosis in Children

Introduction to Asthma Diagnosis

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
The presence of eczema plus wheezing places a child at high risk for persistent asthma throughout childhood, according to the European Respiratory Society guidelines 3
Asthma diagnosis requires at least two abnormal objective tests, not just clinical suspicion, as emphasized by the European Respiratory Society 5

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
Bronchodilator reversibility (BDR) testing, with a ≥12% improvement in FEV1 after bronchodilator, is a key diagnostic test for asthma 1
Fractional exhaled nitric oxide (FeNO) testing, with elevated levels suggesting eosinophilic airway inflammation, is also a recommended diagnostic test for asthma 5

Asthma should only be diagnosed when two or more of the recommended diagnostic tests (spirometry, BDR testing, FeNO testing) are abnormal 5
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 5

Recurrent wheeze is the most important symptom of asthma, not isolated cough, and this child has documented wheezing on examination 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 1
The European Respiratory Society conditionally recommends against using symptom improvement after preventer medication to diagnose asthma 1

If the child is under 5 years old, spirometry may not be feasible, and the diagnostic approach differs significantly, with a careful therapeutic trial with close monitoring potentially being appropriate 1, 5