THE nature of bronchial asthma is still not entirely clear. The basic anomaly seems to be the increased lability of the bronchial tree so that it reacts excessively to a variety of stimuli, including inhalation of allergens, exercise, infection, and emotional stress. There is good evidence that this anomaly is common to children bearing the diagnostic labels of "recurrent wheezy bronchitis" and bronchial asthma.1,2 Some older children whose clinical history clearly points to one specific allergen and in whom skin tests are confirmatory may benefit from desensitization. This is not the case in those sensitive to a wide range of allergens.
The place in therapy of the desensitization of children to the house dust mite is not yet clear. It seems reasonable to advise measures to reduce dust in the home of any asthmatic child and to advocate avoidance of exposure to domestic animals only when there is a