Reversibility of lung function abnormalities in children with perennial asthma.

Extrinsic perennial bronchial asthma was studied by whole-body plethysmography in 118 patients to evaluate the degree and character of functional abnormalities during the asymptomatic "interval phase" of the disease. Study patients were divided into three functional subgroups, and the efficacy of albuterol (salbutamol), a beta-2-sympathomimetic drug, on bronchial obstruction of hyperinflation was analyzed. Response to medication was best in the group with predominant bronchial obstruction without hyperinflation. In contrast, patients with hyperinflation in the presence or absence of bronchial obstruction had only partial reversibility of their pathophysiologic alterations. Hyperinflation usually causes only minor clinical symptoms but tends to develop into irreversible lung damage in the form of "loss of elastic recoil." We suggest that early diagnosis and strict medical management in patients with hyperinflation are mandatory.