THURSDAY, May 27 (HealthDayNews) -- Specialists treating acid reflux disease or chronic sinusitis have long noticed the two ailments tend to go hand-in-hand.
Now, scientists believe they are reaching a better understanding of the link between troubled stomachs and stuffy noses.
Acid reflux disease "is probably not the cause of sinusitis, but it may be participating in some cases," said Dr. Timothy Smith, a professor of otolaryngology and chief of rhinology and sinus surgery at the Medical College of Wisconsin in Milwaukee.
Sinus specialists see the two conditions "intersecting fairly consistently in clinical practice," he added.
Millions of Americans suffer from heartburn and discomfort linked to gastroesophageal reflux disease (GERD), a condition characterized by frequent entry into the esophagus of harsh stomach acids. Besides being uncomfortable, GERD raises risks for more serious conditions, such as esophagitis, Barrett's esophagus and even esophageal cancer.
An estimated 34 million Americans also suffer from chronic sinusitis, which is characterized by inflammation of the nasal passages. The inflammation shrinks the passages so mucus can't drain properly, causing the discomfort and infection that are hallmarks of sinusitis.
And a large proportion of sinus patients are also affected by acid reflux. However, connections between the two ailments have remained unclear.
"When people think of reflux and sinusitis, they're picturing reflux making its way up from the stomach into the nose and sinuses, but it may not be that simple," Smith said.
To start with, there's a lot of anatomical distance to cover between the two areas. In GERD, reflux splashes into the lower esophagus as it breaches a sphincter separating the esophagus from the upper stomach. But to reach the throat, reflux has to break through another sphincter located at the very top of the esophagus.
Dr. Brian L. Matthews, a professor of otolaryngology at Wake Forest University, describes this type of reflux as a less common, distinct condition called laryngopharyngeal reflux (LPR).
With GERD, reflux leaks into the esophagus at a steady rate and is most active during sleep. But in patients with LPR, the reflux occurs more sporadically, occurring maybe three or four times a day during waking hours, Matthews said.
While the esophagus is somewhat toughened to resist reflux, the throat is much more vulnerable to acid damage.
"Once reflux gets into the pharynx, it can also get into the lungs," Matthews explained. "LPR has been implicated in exacerbating asthma, since reflux is an irritant. It might also have the same effect in chronic sinusitis -- it might not be the cause, but it might exacerbate problems that are already there."
That theory could explain the results of a small study conducted in 2002 by researchers at the University of Nebraska. They reported a "modest improvement" of sinus symptoms in patients with both chronic sinusitis and reflux who took the popular anti-reflux medication Prilosec (omeprazole) for 12 weeks.
For his part, Smith believes acid may not have to reach the sinuses or even the throat to exacerbate sinus woes. Instead, GERD or LPR could trigger neurological changes linked to sinusitis.
"Even if we have refluxate only making its way into the lower esophageal region, that may set off some neural mechanism that then causes inflammatory changes in the upper aero-digestive area," he said.
Links between reflux and sinusitis become much clearer in cases involving children. In fact, reflux in children "commonly presents as respiratory-type problems," Matthews said. He explained that in children, the distance between the lower esophagus and the nasal passages is much shorter, so that when reflux occurs it is more likely that acids will reach the nasal area. The good news, however, is that children with reflux tend to outgrow the condition.
Research into links between reflux and sinusitis in adult patients remains "in its infancy," Smith said. But he's optimistic that someday it may yield clues that will "open new treatment pathways for these patients."
In the meantime, treating acid reflux in patients with chronic sinus trouble remains a good idea, experts say, since it may lower symptoms in a subset of patients plagued by both conditions.