Spectrum of asthma in children. I. Clinical and physiological components.

A sample of 315 asthmatic children, representative of the whole range of asthma in childhood, and a control group of 82 children were studied clinically and physiologically from 7 to 14 years of age. The asthmatic children were arbitrarily classified into four grades according to the relative frequency and persistence of their asthma to 14 years of age. Each of these grades could be more clearly defined on analysis of other clinical and physiological characteristics.THE CHARACTERISTICS OF SEVERE PERSISTENT ASTHMA WERE: onset usually in the first three years of life, a high frequency of attacks in the initial year, clinical and physiological evidence of persisting airways obstruction and pulmonary hyperinflation, chest deformity, and impairment of growth. By contrast, mild asthma usually began later in childhood, was episodic, and there was little or no evidence of airways obstruction between attacks. The attacks generally stopped before 10 years of age. In between these two extremes were two intermediate grades.The clinical and physiological characteristics of each grade of asthma at 14 years of age were usually evident by 10 years, and in the most severe grade by 7 years of age. These characteristics provide a sound basis for assessment, management, and prognosis.