Clinical History.—A 17-month-old boy was admitted to the hospital with asthma. He had been suffering from asthma since the age of 4 months and had had two previous hospitalizations for the control of asthmatic attacks. During the intervals, he was doing well, without any difficulty in breathing. There was a strong maternal family history of asthma.
Physical Examination—He was very active and playful and in no distress. Auscultation and percussion revealed decreased breath sounds and hyper-resonance on the left side, except in the basal area. The right side of his chest was clear. The heart was shifted to the right, with the point of maximum impulse at the tip of the xiphoid. Laboratory findings were normal. A technitium Tc 99m macroaggregated albumin lung scan showed no perfusion of the upper lobe of the left lung, but normal perfusion of the lower lobe and of the entire right lung.