Heartburn is the cardinal symptom of acid reflux . This may result in damage to the esophagus causing difficulty swallowing. However, so can allergic esophagus also known as eosinophilic esophagitis.
Recent studies confirm both may be present though allergic esophagus may be missed. This is because of the unawareness of this fact by some gastroenterologists and the common practice to presume acid reflux is the cause. If acid reflux is presumed and the visual and historical clues of acid reflux missed then a biopsy of the esophagus that confirms the characteristic finding microscopically of an abnormal number of the allergy cell, eosinophil, in the esophagus may not be done by the doctor. As a result the role of food allergy in the patient’s symptoms will be not be appreciated.
Adding to the confusion is the knowledge of many pathologists and endoscopy doctors that eosinophils are commonly present in the lower esophagus when acid reflux injury has occurred. However, typically the number of eosinophils is few. The number of eosinophils may not be high enough to separate acid reflux from acid reflux in some patients. A recent study found another allergy cell known as the mast cell, help differentiate allergic esophagitis from acid reflux esophagitis. This study also provides further support that some people have both acid reflux and allergy.
Eosinophils are not normally present in the esophagus but are seen in small numbers under the microscope in biopsies of esophagus due to acid reflux. A count of more than 15-20 eosinophils per high power field (HPF or 40x) is the usual range considered diagnostic of acid reflux though some pathologists use 24 or more. In reflux, up to 7 eosinophils per HPF is considered typical.
Kirsch et al. found a significantly higher number of eosinophils (on average 55/HPF) in acid reflux , along with the presence of mast cells, compared with reflux. However, though 96% of the acid reflux biopsies showed IgE on cells so did 41% of those with acid reflux . This is consistent with some earlier studies that have suggested some people with acid reflux , especially those with more than 7 eosinophils per HPF, also have an allergic component.
This may also explain the failure of acid blocking medications alone to relieve the symptoms acid reflux in some people. The study also again highlights the growing evidence of the importance of biopsies when the gastrointestinal tissue visually appears normal. Without biopsies of normal appearing tissue in people with symptoms microscopic evidence of food allergy or sensitivity is commonly missed. Now that special stains are available for seeing previously difficult to see the allergy cell known as the mast cell, we are finding that this cell is commonly present in gastrointestinal tissue in people with symptoms who have previously been told that they had a normal exam.
Unfortunately, far too many gastrointestinal doctors are still failing to biopsy normal appearing tissue. Sometimes, it feels like despite the accumulating evidence of the importance of biopsies despite normal appearing tissue that seeing change in gastrointestinal doctors habit is like waiting for your dog to bark. Sadly, many people with irritable bowel syndrome have been told they have normal exams when they may have increased mast cells in their intestines and could be offered disease directed curative therapy rather than therapy directed at reducing symptoms combined with the unhelpful “you’re going to have to learn to live with it”.
Are we doing the same or worse with many people with chronic acid reflux symptoms? Post me a comment to let me know your thoughts and experiences. To your healthy gut, healthy life, The Food Doc.
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Reference: Kirsch R et al. “Activated mucosal mast cells differentiate eosinophilic (allergic) esophagitis from gastroesophageal reflux disease” Journal of Pediatric Gastroenterology and Nutrition 2007; 44:20-26.