Acid reflux into the oesophagus, larynx, pharynx or nasopharynx has been suggested as a causal factor in chronic rhino-sinusitis (CRS), which can then be refractory to nasal treatments. A recent review by Flook & Kumar (Rhinology 2011) evaluated the strength of the link between acid reflux and nasal symptoms and CRS.
The authors evaluated 19 studies including those of proton pump inhibitors therapy. Four adult case-controlled studies showed more acid reflux events/symptoms in refractory CRS patients. Paediatric cohort studies showed more reflux events in rhinosinusitis patients than the general paediatric population, but they are not conclusive. Many of the papers did not use robust CRS diagnostic criteria for inclusion into studies and take no confounding factors into consideration.
The authors concluded that the evidence of a link between acid reflux with chronic sinusitis or any nasal symptoms is poor with no good randomised controlled trials available. The few adult studies that show any link between acid reflux and nasal symptoms were small case-controlled studies with moderate levels of potential bias. They found that there is not enough evidence to consider anti-reflux therapy for adult refractory CRS and there is no evidence that acid reflux is a significant causal factor in CRS.