Intended for healthcare professionals


Exhaled nitric oxide in the diagnosis of childhood asthma

BMJ 2009; 339 doi: (Published 29 December 2009) Cite this as: BMJ 2009;339:b5418
  1. Malcolm Brodlie, joint Medical Research Council and Cystic Fibrosis Trust clinical research fellow1,
  2. Michael C McKean, consultant respiratory paediatrician2
  1. 1Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne NE2 4HH
  2. 2Paediatric Respiratory Unit, Newcastle upon Tyne Hospitals NHS Foundation Trust, Royal Victoria Infirmary, Newcastle upon Tyne NE1 4LP
  1. michael.mckean{at}

    A small but important piece of the clinical jigsaw

    Although asthma is the most common chronic disease of childhood,1 it remains a clinical diagnosis.2 Common symptoms include recurrent wheezing, cough, difficulty in breathing, and chest tightness, but no agreed “gold standard” definition exists.2 Improvements in symptoms and lung function seen after adequate treatment often provide retrospective confirmation of the diagnosis.2

    Accurate diagnosis of asthma in children may be difficult but is vital for two reasons. Firstly, a correct diagnosis is essential for the institution of guideline based treatment, which may involve specialist referral; this is needed to avoid the morbidity and rarely mortality associated with poorly controlled disease.2 Secondly, the exclusion of asthma prevents potential harm from inappropriate anti-asthma treatment and may highlight other crucial diagnoses such as cystic fibrosis.3

    Asthma is a heterogeneous disease, and data from large population based studies have informed the concept of different patterns or “phenotypes” in children who wheeze.4 Importantly, preschool children who wheeze only when they have viral respiratory tract infections form a discrete and largely self resolving group in which wheeze is independent of allergic sensitisation.4 Wheeze associated with multiple triggers and allergic sensitisation, recognised as the “classic” atopic asthma phenotype, is responsible for most clinically important disease in school aged children but may also …

    View Full Text

    Log in

    Log in through your institution


    * For online subscription