No abstract

The clinical value of measuring fractional exhaled nitric oxide (FeNO) in asthma is not clear. We aimed to assess whether FeNO can reliably predict clinical outcomes in asthma treated with inhaled corticosteroids (ICS). We also evaluated whether its predictive role is influenced by different inflammatory phenotypes of asthma.We conducted a systematic review focusing on five clinically relevant questions. Two authors independently screened search results, extracted data and assessed quality of the included studies. Data were synthesised by qualitative methods.12 prospective studies were included, answering partly three of the five questions. In steroid-naïve asthma, a high FeNO level probably predicts good response to ICS. In ICS-treated asthmatics, a low FeNO level probably predicts low risk of exacerbation, and the patient is unlikely to benefit from increasing ICS dose. There were scarce data to conclude whether FeNO predicts exacerbations when ICS treatment is stopped in well-controlled asthma. Only one study reported results separately in different asthma phenotypes.The current evidence on the predictive value of FeNO and its role in the management of asthma is incomplete. Future studies should focus on clinically meaningful questions and probably target only eosinophilic phenotypes where FeNO is best associated with the activity of airway inflammation.

No abstract

Early childhood wheezing is associated with asthma later in life. However, the high spontaneous recovery rate and the lack of firm predictors for persistence of wheezing complicates the development of evidence-based guidelines for long-term management of wheezy infants and toddlers. Our aim was to define variables that could be used to identify wheezy individuals younger than 3 years of age who would continue to be symptomatic at school age. The method used was a questionnaire-based cross-sectional survey of 2,027 randomly chosen, 6-13-year-old school children. Altogether 1,829 (90%) questionnaires were returned. Emergency medical care had been sought for 186 (10.2%) children for wheezing during the first 3 years of life, and only 17.2% of these children had received similar emergency treatment during the 12 months preceding the survey. The total proportion of children with current asthma at school age was 11.4%. A logistic regression analysis indicated that for the early wheezers, a family history of asthma, an itchy rash or food allergy, and exposure to tobacco smoke at home before the age of 3 years, were all independently associated with symptom persistence until school age. Among all wheezy children younger than 3 years, those who have a history of food allergy, itchy rash, asthma occurrence in a sibling or parent, or are exposed to tobacco smoke during the first years of life are at highest risk for symptom persistence until school age.