Asthma is the leading chronic disease in children in the Western world, affecting 5–20% of school-aged children in Europe [1]. Childhood asthma is a serious public health problem. First, it causes considerable morbidity with high frequencies of sleep disturbances, emergency visits, school absence, and limitations of physical activity, and healthcare utilisation [2]. As quoted by Hedlin et al. [3] in this issue of European Respiratory Review, asthma is the fourth most common cause of disability-adjusted life years for children aged 10–14 yrs. Secondly, as asthma is associated with reduced lung function growth, and lung function at a young age is a determinant of lung function in adult life, optimal treatment is of major concern for long-term prognosis [4, 5].
Several efforts have been made to improve knowledge on childhood asthma in order to unravel pathogenesis, and improve treatment modalities and monitoring strategies, as reflected by almost 2,000 papers published on asthma and children in 2011 and 2012. In this issue, Hedlin et al. [3], in an extensive overview, bring together all novel findings on paediatric asthma and delineate future directions.
The GA2LEN initiative is an inspiring example of how international collaboration may take a clinical problem, such as problematic severe asthma, further. The proposed work-up of asthmatic children who are uncontrolled on high doses of medication and the classification into “difficult to treat” or “therapy resistant” provides the clinician with practical tools on how to treat these patients.
However, several questions remain to be answered. As pointed out by Hedlin et al. [3], heterogeneity of asthma in general and problematic asthma …