Severe childhood asthma

Abstract

Sir—Marco Rabusin and colleagues’ case report (Jan 3, p32) of a child with severe asthma contains several lessons, some arguably more important than the post-mortem diagnosis of Churg-Strauss syndrome. From the history given it is clear that the child was atopic and at risk of further attacks of acute asthma, having been admitted to hospital three times during the previous 6 months. The child had been treated at home with nebulised salbutamol and had received 20 mg over 12 h before his final and fatal admission. Regular use of 2-agonists alone is associated with down-regulation of the 2-receptor, which leads to a cycle of increased dependence on 2agonists and an increase in bronchial hyper-responsiveness. Studies of the epidemics of asthma deaths from the 1960s and the 1980s showed that reliance on short-acting bronchodilators was associated with increased risk of death, particularly when delivered by home nebuliser. The recently described Campbell and coworkers report of reduction in asthma mortality has been attributed to a rise in the use of inhaled corticosteroids. A 2-year-old child with 3 recent hospital admissions for acute asthma should be treated with inhaled corticosteroids and oral steroids should be used early during exacerbations. In this situation it is vital for parents to understand the way these drugs should be used so that they do not allow their prejudices against the use of steroids to interfere with effective treatment of such a serious condition. A further point illustrated by this case relates to the availability and use of home nebulisers. Home nebulisers are useful for children who do not tolerate any other delivery system. Risks develop if nebulised bronchodilators are administered in higher than recommended doses (including more frequent administration than 4 h) and if hospital referral is not made when there is an inadequate response. There can be an inclination to give the child “just one more dose” to see if he “responds as he usually does”, but the child may become increasingly hypoxic with no monitoring of oxygen saturation available. Data from New Zealand suggest that inappropriate long-term use of a home nebuliser may delay institution of other effective therapy, in some cases of asthma deaths. A child with severe asthma must be treated with inhaled and sometimes oral corticosteroids. Home nebulisers may be extremely dangerous in this situation. These rules should apply to any child with severe asthma so that preventable deaths are avoided.