To systematically review published literature describing the association between reflux and upper airway symptoms in children.
Structured MEDLINE search of English-language articles published since 1966.
We selected articles examining reflux in conjunction with stridor, apnea, sudden infant death syndrome, life-threatening events, and laryngomalacia. Studies that focused on lower airway symptoms or adults were excluded.
Articles were abstracted for patient factors, elements of study design, methods of reflux diagnosis, and definition of pathologic reflux.
Ninety-nine articles were identified, 56 of which specifically examined reflux and upper respiratory symptoms in children. Of these, 10 compared reflux incidence in symptomatic patients and a set of predetermined control patients, while the remainder reported prevalence data only. Overall, symptomatic patients were diagnosed with reflux frequently, with a range from 27% to 100%. In studies that attempted to compare patients with controls, only 2 provided statistical comparisons of the patient groups, and none adjusted for confounding owing to study design. There was marked heterogeneity in methods used to diagnose reflux in the studies reviewed, with only 34% using dual-channel pH testing; definitions of pathologic reflux were also variable.
Evidence seems to support the hypothesis that reflux is associated with upper airway symptoms in children. However, the strength of this correlation and the risk of upper airway symptoms attributable to reflux are difficult to determine given the limitations of available literature. Future research studies should seek standard reflux testing methods, clear comparison groups, and more rigorous statistical methods.