Skin reactivity and eosinophil count in relation to the outcome of childhood asthma.

The aim of this study was to determine whether an association can be found between childhood skin reactivity and the outcome of asthma in young adulthood in a group of 406 asthmatic children, of whom 348 (86%) could be followed up in adulthood. A complete data set on skin tests and eosinophil count was available in 259 allergic subjects. They were stratified into three classes, according to initial skin test score in childhood. An increase in skin reactivity was noted from childhood to adulthood, while the differences in skin reactivity between the three classes remained significant. In childhood, a marked difference in total eosinophil count was found between the classes. Towards adulthood, a decrease in eosinophil count was noted, and the differences between the classes were no longer significant. The children with lowest skin reactivity also had the lowest symptom score in childhood. In adulthood, the prevalence of respiratory symptoms in this class was lower than in the other two classes. The prevalence of bronchial responsiveness to histamine was lowest in subjects with the lowest skin test score in childhood. Ventilatory parameters revealed no differences between the three classes. We conclude that although a low skin reactivity in childhood might be associated with a relatively favourable prognosis for asthma symptoms in adulthood, there is only limited evidence to support this hypothesis in our study.