Evidence-based recommendations for the use of each of the tests considered for asthma diagnosis in children aged 5–16 years in primary, secondary or tertiary care
| Recommendation | Remarks | |
| PICO 1. In children aged 5–16 years under investigation for asthma, should the presence of the symptoms wheeze, cough and breathing difficulty be used to diagnose asthma? | • The task force recommends against diagnosing asthma based on symptoms alone (strong recommendation against the intervention, moderate quality of evidence) | • Recurrent wheeze, cough and breathing difficulty are key symptoms of asthma. The task force considers a history of recurrent reported wheeze or wheeze on auscultation as the most important symptom of asthma • Children with chronic cough (i.e. cough for >4 weeks) as the only symptom are unlikely to have asthma and should be investigated according to the ERS guidelines for chronic cough in children [32] and a referral for further investigations to exclude differential diagnoses should be considered |
| PICO 2. In children aged 5–16 years under investigation for asthma, should an improvement in symptoms following a trial of preventer medication be used to diagnose asthma? | • The task force recommends against using an improvement in symptoms after a trial of preventer medication alone to diagnose asthma (conditional recommendation against the intervention, based on clinical experience) | • The task force did not find any evidence for or against a trial of preventer medication to diagnose asthma in children aged 5–16 years • Despite the lack of evidence, based on clinical experience, the task force members agreed that a trial of preventer medication can be considered; but only in symptomatic children with abnormal spirometry and negative bronchodilator response. In such cases, the objective tests spirometry and, if indicated, BDR should be repeated after 4–8 weeks |
| PICO 3. In children aged 5–16 years under investigation for asthma, should spirometry testing be used to diagnose asthma? | • The task force recommends spirometry as part of the diagnostic work-up of children aged 5–16 years with suspected asthma (strong recommendation for the intervention, moderate quality of evidence) | • An FEV1/FVC <LLN or <80%, or an FEV1 <LLN or <80% pred should be considered supportive of an asthma diagnosis. It is important to be aware that not all children are able to perform a sufficient FVC manoeuvre, resulting in a false normal FEV1/FVC ratio • A normal spirometry result does not exclude asthma |
| PICO 4. In children aged 5–16 years under investigation for asthma, should BDR testing be used to diagnose asthma? | • The task force recommends BDR testing in all children with FEV1 <LLN or <80% pred and/or FEV1/FVC <LLN or <80% (strong recommendation for the intervention, based on clinical experience) | • Consider an increase in FEV1 ≥12% and/or ≥200 mL following inhalation of 400 μg SABA as diagnostic of asthma • BDR <12% does not exclude asthma • Most task force members consider BDR testing when baseline spirometry is normal if the clinical history is strongly suggestive of asthma |
| PICO 5. In children aged 5–16 years under investigation for asthma, should FeNO testing be used to diagnose asthma? | • The task force recommends measurement of FeNO as part of the diagnostic work-up of children aged 5–16 years with suspected asthma (strong recommendation for the intervention, moderate quality of evidence) | • A FeNO value ≥25 ppb in a child with asthma symptoms should be considered as supportive of a diagnosis of asthma • A FeNO value <25 ppb does not exclude asthma |
| PICO 6. In children aged 5–16 years under investigation for asthma, should PEFR variability be used to diagnose asthma? | • The task force recommends against PEFR variability testing as the primary objective test on its own to diagnose asthma in children aged 5–16 years (conditional recommendation against the intervention, moderate quality of evidence) | • Other objective tests are preferred, but a PEFR variability test can be considered in healthcare settings lacking other objective tests • If a PEFR variability test is used the result should be based on 2 weeks of measurements, ideally using electronic peak flow meters • A cut-off of ≥12% in PEFR variability should be considered a positive test • A PEFR variability of <12% does not exclude asthma |
| PICO 7. In children aged 5–16 years under investigation for asthma, should allergy testing be used to diagnose asthma? | • The task force recommends against the use skin-prick tests to aeroallergens as diagnostic tests for asthma (strong recommendation against the intervention, moderate quality of evidence) • The task force recommends against the use of serum total and specific IgE tests as diagnostic tests for asthma (strong recommendation against the intervention, moderate quality of evidence) | |
| PICO 8. In children aged 5–16 years under investigation for asthma, should direct bronchial challenge testing including methacholine and histamine be used to diagnose asthma? | • The task force recommends a direct bronchial challenge test using methacholine in children aged 5–16 years under investigation for asthma where asthma diagnosis could not be confirmed with first-line objective tests (conditional recommendation for the intervention, low quality of evidence) | • A PC20 value of ≤8 mg·mL−1 should be considered as a positive test • The task force found no evidence for or against performing histamine challenge tests in children under investigation for asthma |
| PICO 9. In children aged 5–16 years under investigation for asthma, should indirect bronchial challenge testing including exercise and mannitol be used to diagnose asthma? | • The task force recommends an indirect bronchial challenge test using a treadmill or a bicycle in children aged 5–16 years under investigation for asthma with exercise related symptoms where asthma diagnosis could not be confirmed with first line objective tests (conditional recommendation for the intervention, moderate quality of evidence) | • A fall in FEV1 of >10% from baseline should be taken as a positive test • A mannitol challenge can be considered as an alternative to exercise challenge. However, due to its limited availability in most countries, and the fact that children often find the test unpleasant, mannitol challenge should be best avoided in favour of other challenge tests |
PICO: Population, Intervention, Comparator and Outcome; BDR: bronchodilator reversibility; FeNO: exhaled nitric oxide fraction; PEFR: peak expiratory flow rate; ERS: European Respiratory Society; FEV1: forced expiratory volume in 1 s; FVC: forced vital capacity; LLN: lower limit of normal; SABA: short-acting β2-agonist; PC20: provocative concentration of methacholine that results in a 20% drop in FEV1.