She was born at full term by normal vaginal delivery after an uncomplicated gestation. At the age of 7 weeks she experienced a similar period of difficulty breathing. She was then diagnosed with acute bronchiolitis. A nasal aspirate was positive for respiratory syncytial virus (RSV) as determined by immunofluo-rescence. Chest radiograph showed hyperexpansion and interstitial markings consistent with bronchiolitis. Bronchoscopy showed normal airway anatomy. She was transferred to the pediatric intensive care unit for 4 days because of continuous hypoxemia (pulse oximeter readings <90%) during the first hours in the hospital. She was mechanically ventilated. Treatment with nebulized salbutamol and ipratropium bromide, did not have a significant effect. After day 2 she improved and after 10 days she was discharged from the hospital. During the following months she experienced 3 relapses of moderate wheeze without the need for hospital admission. There was no family history of heart or lung disease, cystic fibrosis, congenital malformations or other disorders. None of her family members had asthmatic or allergic symptoms.
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