The wheeze generally increases with activity and decreases during quiet periods. At first, wheezing may be mistaken for bronchiolitis, especially during respiratory syncytial virus season. As wheezing continues, it may be mistaken for asthma or cystic fibrosis. The baby looks well and happy despite the chronic wheeze. Vital signs, including respiratory rate and oxygen saturation, are normal.
Lungs have good air entry.
The typical abnormality is of a wheeze throughout expiration that sounds the same in all lung fields. It is a coarse expiratory sound, which has been described as expiratory stridor. No asymmetry to the breath sounds is present. Voice is normal. Since some children have concomitant laryngomalacia, abnormal sounds upon inspiration also may be present.