Coughs and wheezes spread diseases: but what about the environment?

One disagreeable part of growing up is the inevitable encounters with respiratory viruses which, in about half the population, will have led to at least one wheezing episode before school age. For many the symptoms of wheeze are trivial and require no or only intermittent treatment but, for others, winter in particular turns into a nightmare of recurrent hospital admissions punctuated by brief periods of perfect health before the next viral infection takes hold. All concerned feel powerless in both prevention and treatment; for many families it is inevitable that they use childcare facilities, a fertile virological breeding ground. In any case, the possible protective effects of viral infections against later asthma (below) should give pause for thought before removing the child from the crèche. Although there is some evidence that intermittent high dose inhaled corticosteroids¹ or oral montelukast^2–4 may be adequate treatment, many children with viral associated wheeze end up being prescribed several courses of oral prednisolone each winter. The treatment of severe preschool viral induced symptoms is among the most taxing and least rewarding challenges in childhood wheezing disorders.

The hypothesis generating paper by Murray et al in this month’s Thorax raises some hope for a potential new preventive approach.⁵ This group has extended previous work in adult asthmatics⁶—in which they showed an apparent synergy between viral infection, and allergen sensitization and exposure—into a group of unselected children with asthma, the youngest of whom were 3 years old. In a multivariate analysis they showed that children admitted to hospital with an asthma exacerbation (but not stable asthmatics or non-asthmatic controls) were significantly more likely to be infected with a respiratory virus and to have been exposed to an allergen to which they …