Determination of airway hyper-reactivity in asthmatic children: a comparison among exercise, nebulized water, and histamine challenge.

An easy and accurate method of assessing bronchial hyper-reactivity could be of great value in identifying and classifying the degree of severity of asthma in children. The sensitivity and specificity of three methods of provocation, ie, histamine, nebulized water, and exercise, were compared in 20 asthmatic and 20 control children between ages 5 and 13 years. Three clinical categories of severity ranging from slight (Group 1) through moderate (Group 2) to severe asthma (Group 3) were identified. The three methods were compared in each subgroup for detecting a tendency to bronchospasm. An inverse correlation (-0.57) was found between the histamine dose and clinical degree of severity, whereas distilled water and exercise proved to be too insensitive for identifying Group 1 asthmatics. Histamine challenge in children is a safe and sensitive technique for identifying asthma and for monitoring the severity of the disease during follow-up.