Is spirometry essential in diagnosing asthma? Yes.

> ‘I’m commonly consulted by children, whose parents report they were “coughing and wheezing all night”. These kids often appear well and their lung function may be normal.’ Asthma is a chronic respiratory disease characterised by fluctuating respiratory symptoms and reversible airflow obstruction.1,2 Confirmation of the diagnosis hinges on demonstrating airflow obstruction varying over time. Patients with undiagnosed asthma who consult repeatedly with symptoms ranging in severity3 may demonstrate perfectly normal spirometry. As there is no single ‘gold standard’ test, clinical asthma diagnosis is based on evidence of recurrent respiratory symptoms; reversibility with anti-asthma treatment; and variable airflow obstruction. Demonstrating any, or all three, of these features in a clinical setting is challenging: the disease fluctuates. The diagnosis is clear cut if spirometry in a patient with a history suggestive of asthma demonstrates airflow obstruction with reversibility. …