Pollen Allergy and Food Sensitivity: The Oral Allergy Syndrome and Food Intolerance

Pollen Allergy and Food Sensitivity: The Oral Allergy Syndrome and Food Intolerance

Oral allergy syndrome (OAS) is a well-known but little understood condition. It is characterized by a burning sensation or mouth pain and swelling when you eat certain foods that react to pollen that you are allergic to. Interestingly, the specific foods that cause this reaction are well established to cross-react with certain trees, grass or weed pollen, dust mites, or latex. There are common groups of foods that are associated with certain nasal allergies. For example, a ragweed allergy often causes an oral or intestinal reaction after eating melons or bananas, but usually not other foods. Birch pollen is often associated with reactions to numerous foods, as is a latex allergy. The explanation for these reactions includes similarities in protein structures as well as some chemicals in the foods.

Although this reaction is well documented in the allergy literature, it is not commonly recognized or diagnosed by most physicians, including some allergists and many stomach specialists. Various allergy websites contain lists of the most common foods associated with certain pollens, dust mites or latex. However, a comprehensive list that is easy to read or interpret can be difficult to find. The names of some pollens or the common connections between a group of pollens and a group of foods can also be confusing.

In its classic form, OAS should be easy to recognize. After eating a food associated with a pollen to which you are allergic, you will experience an almost immediate burning sensation in your mouth or throat, with or without swelling. However, it is generally accepted that in medicine symptoms often do not appear in a “classic” or typical way for a given person. In other words, doctors learn “patients don’t read the textbooks.” Therefore there may be fluctuations in the response, e.g. B. Swelling or narrowing of the throat, burning when swallowing, lumps in the throat, or difficulty swallowing, but not related to what you have eaten or what is happening to you.

You or your doctor may misinterpret your symptoms. Often people just assume it happened because they choked on food that was poorly chewed, swallowed too quickly, or eaten or drunk too hot or too cold. A disorder of the esophagus (swallowing tube), particularly acid reflux with a hiatal hernia, is generally believed to be the cause. Acid reflux can cause a narrowing of the esophagus called a stricture or ring, which can lead to food sticking. However, this is usually associated with heartburn or food sticking, which then leads to an upper endoscopy or scope examination. In other cases, particularly in older people, a neurological disorder such as stroke or Parkinson's disease is blamed. Sometimes doctors decide that your symptoms are due to a nervous reaction or neurosis, which in the past was called globus hystericus. The hystericus part of the term is now usually reduced to the shorter globus or globus feeling, especially since it has not been proven to be a psychiatric problem. However, Globus may be the diagnosis you've arrived at if your complaint is that you feel a lump in your throat and an "evaluation" doesn't seem to turn up anything, even if OAS hasn't been considered or ruled out.

An unusual condition recently recognized in the field of gastroenterology (diseases of the stomach and intestines) that may be associated with one or a variant of OAS is called eosinophilic esophagitis (EE) or allergic esophagitis. It was first described in the pediatric population but is now known to occur in adults. Classically described in teenagers and young men who experienced foods without heartburn or acid reflux symptoms, it is associated with a strange appearance of the esophagus on endoscopy (examination of the upper gastrointestinal tract with an illuminated scope). What the doctor who performs the scope sees is that the esophagus resembles a cat's esophagus. This means it looks like it has rings (cats have cartilage rings in their esophagus, we don't) and this is called an "annular esophagus" or felinization of the esophagus. Biopsy of such an annular or felinized esophagus (which also often becomes narrowed, leading to food adhesion) reveals microscopic signs of allergy. The lining shows numerous eosinophils, a reddish-pink appearing white blood cell that is characteristic of allergic conditions. These eosinophils release chemicals like histamine, which trigger swelling, pain and tissue damage.

Food allergies are common in EE, although sometimes screening for food allergy by conventional skin tests or IgE blood tests is negative. Treatment is avoidance of known food allergens and swallowed nasal steroid sprays designed for use in the nose for nasal allergies. Although not yet specifically proven, eosinophilic esophagitis (EE) may be a variant of OAS.

Eosinophilic gastroenteritis and eosinophilic or allergic colitis also exist and can be diagnosed through biopsies of the stomach, small intestine, and colon, respectively. Allergic colitis typically occurs in infants with a cow's milk protein allergy. It presents as colicky abdominal pain, diarrhea, weight loss, and bloody diarrhea in an infant on cow's milk formula or sometimes in breastfed infants whose mother drinks a lot of cow's milk.

Allergic gastroenteritis occurs in any age group, typically presenting as abdominal pain with or without intestinal blockage or perforation. Diarrhea; Anemia; weight loss; and microscopic bleeding in the intestinal tract, also known as occult blood in the stool. Such bleeding can only be detected by special chemical stool tests known as fecal occult blood tests (FOBT) or stool guaiac tests.

At least some people with food intolerances that don't make sense based on limited food diary information, blood tests, biopsies, or allergy testing may have a form of OAS. In other words, the presence of known pollen or latex allergies may predispose to reactions to foods known to intersect with allergies specified in the OAS. However, instead of the classic symptoms of oral allergy syndrome, other stomach and intestinal symptoms or even non-gastrointestinal symptoms may also occur.

Support for this concept can be found in detailed screening of individuals for food intolerances. Individuals with known pollen or latex allergies, known food allergies or intolerances, including gluten intolerance (celiac disease) and casein intolerance, will be asked to complete a series of symptom assessments and severity rating scales, followed by a strict elimination diet. This is followed by a reassessment of the symptom response while reintroducing the foods one at a time while monitoring recurrence.

This type of analysis is the basis for the Neopaleo specific diet. In the near future, online symptom assessments and food intolerance screening, as well as individualized nutritional recommendations, will be available at www.thefooddoc.com. An online diet symptom diary will also be available. A simplified table of common foods that can cross-react with the broad categories of pollen allergens and latex allergies is available. Food intolerances are more commonly recognized as a common cause of illness and symptoms. Individual specific dietary recommendations and elimination diet trials can be helpful in discovering possible connections to what you eat and how you feel.

Copyright 2006 The Food Doc, LLC. All rights reserved.

Inspired by Dr. Scot Lewey