Laryngomalacia is the most common cause of
stridor in children. Previous studies using
barium esophagrams or single-probe esophageal pH testing have indicated that 68% to 80% of infants with
laryngomalacia have reflux. A recent study in a large series of pediatric patients has shown that these 2 testing modalities are relatively insensitive in detecting reflux when compared with 24-hour double-probe pH testing. This study was undertaken to determine the incidence and frequency of reflux in children with
laryngomalacia by use of 24-hour double-probe pH monitoring. Twenty-four children with endoscopically diagnosed
laryngomalacia underwent 24-hour double-probe pH testing. The distal probe was placed in the lower esophagus, and the proximal probe was placed just above the cricopharyngeus immediately posterior to the larynx. All 24 (100%) children had pharyngeal
acid exposure as judged by the proximal pH probe. These children had a mean of 15.21 episodes of reflux to the level of the pharynx during the 24-hour study period. In contrast, only 16 (66%) children had abnormal
acid exposure as measured by the distal esophageal probe. These results indicate that essentially all children with
laryngomalacia have reflux of gastric acid to the pharyngeal level. Multiple authors have documented the detrimental effects of
acid and the accompanying
pepsin in the larynx and tracheobronchial tree. Persistent
laryngeal edema is an almost universal finding in patients with reflux to the pharyngeal level and is a common finding in children with
laryngomalacia. In some patients with
laryngomalacia, reflux may be the primary cause of their airway compromise, whereas in others it may be a significant cofactor exacerbating a preexisting neurologic or anatomic abnormality.