Asthma phenotypes in children

Published on December 29, 2011 Archived on January 31, 2018   35 min

Other Talks in the Category: Biochemistry

ANDREW BUSH: Thank you for listening to this online lecture. My name's Andrew Bush. I'm professor of Pediatrics at Imperial College.
The aim of my presentation is to discuss the approach to the child with 'nightmare asthma', to demonstrate a protocol for the assessment of problematic, 'severe asthma', and review the potential phenotype-driven treatment options that we have available to us.
The basics of asthma are very straightforward. Most children with asthma are very easily treated. Most respond to modest doses of inhaled corticosteroids, and neither need, nor get no benefit from higher doses, and high dose inhaled corticosteroids may be harmful. So the question faced with a child with nightmare asthma is, what makes this child's asthma different from the run of the mill asthma and makes it difficult to treat?
We can get a clue from this study from North America, which was a study in futility. The aim of this study was to assess whether azithromycin or a leukotriene receptor antagonist was a better add-on therapy for children who were still symptomatic, despite inhaled corticosteroids and inhaled long-acting bronchodilator. 292 children were assessed for eligibility, but only 55 could be randomized. The others were excluded due to nonadherence or they did not have asthma, and this underscores the fact that many children with so-called "difficult asthma," in fact, do not have any such thing.
This study, looking at daily monitoring of exhaled nitric oxide was an excellently conducted piece of work in over 150 children. It was a 30-week study, there were on a reasonable dose of inhaled corticosteroids, and they were randomized to either a telemonitoring of exhaled nitric oxide and a detailed management program of inhaled corticosteroids, with regular and detailed titration of the dose, or the standard symptom-based steroid management protocol. They were telephoned every three weeks, the end-point was symptom free days, and the results showed that the time to exacerbation and symptom free days were exactly the same in the two groups. In other words, standard care was just as good as sophisticated monitoring of airway inflammation.