The dark side of the moon: Severe therapy-resistant asthma in children

Problematic severe asthma is the term used to describe children whose asthma is not responsive to standard therapy with high-dose inhaled corticosteroids and additional controllers. These children need to be assessed by a step-wise systematic protocol in order to confirm the diagnosis, evaluate co-morbidities, assess the adherence to treatment, and finally evaluate the basic management. More than half of these children have "difficult-to-treat asthma", which improves if the basic management is correct. Children whose asthma remains uncontrolled despite resolution of any reversible factors are termed "severe therapy-resistant" asthmatics; for them, an individualised treatment plan is developed after a detailed and invasive protocol of investigation. Therapeutic options for these patients can be divided into medications used in lower doses for children with less severe asthma, and those used in other pediatric diseases but not for asthma. Most treatments are unlicensed and there is a lack of high-quality evidence. Children with recurrent severe exacerbations, in particular in the context of good baseline asthma control, are particularly difficult to treat, and there is no evidence on which therapeutic option to recommend. International collaborations, using standard protocols of investigation, are needed to better understand mechanisms of severe therapy-resistant asthma and to deliver evidence-based treatments in the future.