Gastro-oesophageal reflux (GORD) and its extraoesophageal manifestations present with a variety of symptoms in both adult and paediatric populations. In children the effects of refluxate above the upper oesophageal sphincter (UES) has been implicated as a contributory factor in the underlying pathological processes of a number of conditions including apnoea, asthma, chronic cough, subglottic stenosis, chronic rhinosinusitis and otitis media.~The absence of typical symptoms in addition to the inability to obtain a formal symptom history from a young paediatric population contributes to the difficulty in establishing a diagnosis.~At present there are no studies or data directly measuring extraoesophageal reflux and its correlation to oesophageal pH monitoring in children. As a result there is no baseline data for a paediatric population and subsequently no measureable definition of a significant extraoesophageal reflux event. There is a poor correlation between reflux events measured with an oesophageal probe and extra-oesophageal symptoms of reflux. Studies have demonstrated that 51% of patients without pharyngeal reflux had abnormal distal oesophageal pH studies.~This is secondary to both technical concerns regarding the ability of such probes in detecting aerosolized and vapour forms of reflux in the pharynx and due to the inadequacy of the definition of a significant reflux event above the upper oesophageal sphincter. Moving cephaled (upwards) within the upper aerodigestive tract will result in shorter, higher pH events that may not be recognised using traditional oesophageal analysis, which define a pH<4 as defining a significant oesophageal reflux event.~The use of twenty-four hour oesophageal pH monitoring is regarded as the established technique for diagnosis of GORD, however this technique has been less reliable for detecting extra-oesophageal reflux.~The Dx-pH Measurement system (Dx-pH; Respiratory Technology Corp., San Diego, CA) is a sensitive and minimally invasive transnasal device for detection of aerosolized extra-oesophageal acid reflux in the posterior oropharynx.~The investigators intend to use the Dx-pH measurement system and the Peptest salivary pepsin assay (RBiomed, UK) in children already undergoing oesophageal pH studies. The investigators aim to assess the feasibility of these systems in a paediatric population,to provide baseline data and to validate its use in measuring extra-oesophageal reflux events in children. These results will be correlated against symptom questionnaire scores and the results of the 24 hour oesophageal pH study results.~The investigators' results will guide further interventional studies in this area, with the eventual aim of improving diagnosis and guided treatment for the extra-oesophageal manifestations of GORD
Gastro-oesophageal reflux (GORD) and its extraoesophageal manifestations present with a variety of symptoms in both adult and paediatric populations. In children the effects of refluxate above the upper oesophageal sphincter (UES) has been implicated as a contributory factor in the underlying pathological processes of a number of conditions including apnoea, asthma, chronic cough, subglottic stenosis, chronic rhinosinusitis and otitis media. The absence of typical symptoms in addition to the inability to obtain a formal symptom history from a young paediatric population contributes to the difficulty in establishing a diagnosis. At present there are no studies or data directly measuring extraoesophageal reflux and its correlation to oesophageal pH monitoring in children.~The use of twenty-four hour oesophageal pH monitoring is regarded as the established technique for diagnosis of GORD, however this technique has been less reliable for detecting extra-oesophageal reflux. The investigators intend to use the Dx-pH Measurement system, a sensitive and minimally invasive transnasal device, to assess the feasibility and validate its use in a paediatric population.