Pathophysiology And Associated Conditions gastroesophageal acid reflux

Pathophysiology And Associated Conditions

Transient LES relaxation is the primary mechanism of GERD. It results from a vaso-vagal reflex triggered by stretch receptors of the proximal stomach. Studies have indicated that most reflux episodes are acidic. However, according to one study, 28% of episodes were only weakly acidic and 10% of episodes were weakly alkaline. Numerous factors may influence the symptoms of GERD. Delayed gastric emptying, volume of gastric content, quantity and acidity of refluxed contents, ability of the esophagus to clear this material, LES function, and the resistance of the esophageal tissue can influence reflux symptoms. Some researchers have proposed that patients with GERD can be categorized further as having erosive esophagitis,nonerosive reflux disease, and Barrett’s esophagus.( Zerbib F, et al ,2005)

Gastritis 

There is conflicting evidence regarding the role that Helicobacter pylori may play in GERD pathology. There are various studies that have looked at treatment of gastritis by eradicating H. pylori and the effects of treatment on concurrent GERD symptoms. The results of these studies vary from showing improvement to showing worsening of GERD symptoms. Research regarding inflammation in the gastroesophageal junction, or cardia, has indicated that the presence of erosive GERD or H. pylori gastritis is associated with the inflammation. In addition, GERD and carditis are associated with intestinal metaplasia at the gastroesophageal junction.( Malfertheiner P,2005)

Esophagitis

Esophagitis is common with GERD and may be classified as erosive or nonerosive with the severity based on the number and location of mucosal breaks. Other types of esophagitis, such as eosinophilic esophagitis, present with similar symptoms as GERD and are commonly misdiagnosed. The common presentation of eosinophilic esophagitis is dysphagia and food impaction. Additional symptoms may include epigastric pain, emesis, weight loss, and failure to thrive. The diagnosis is based on a histologic finding of greater than 20 eosinophils per high-powered field in the esophageal squamous mucosa. This condition also presents with motor disturbances that may cause food impaction in the absence of strictures. Manometry shows high amplitude long-duration waves in the distal esophagus particularly at night. The symptoms often respond to elimination or elemental dietary regimens and antiallergy treatment. (Pasha SF,, et al ,2006)Standard skin-prick tests measure type 1 hypersensitivity reactions, which are typically  mediated by immunoglobulin E (IgE). (It is possible to have a positive skin test but normal blood levels of IgE on a radioallergosorbent test [RAST].) However, these tests do not diagnose many food-allergy reactions, which are frequently IgG-mediated. Thus, IgG testing can offer additional insights that are frequently missed with standard skin-prick tests.( Luis AL et al ,2006)