Pollen Allergy and Food Sensitivity:
The Oral Allergy Syndrome and Food Intolerance
By Dr. Scot
Oral allergy syndrome (OAS) is a well-recognized but
little known condition. It is characterized by burning sensation or
mouth pain and swelling when they eat specific foods that cross react
to pollens to which you are allergic. Interestingly, the specific
foods causing this reaction are well established to cross react with
certain trees, grass, or weed pollens, house dust mite or latex.
There are common groups of foods that cluster with certain nasal
allergies. For example, ragweed allergy commonly causes an oral or
gut reaction after eating melons or bananas but usually not other
foods. Birch tree pollen is commonly associated with reactions to
numerous foods as is latex allergy. The explanation for these
reactions include similarities in protein structures as well as some
chemicals in the foods.
Though this reaction is well documented in the allergy
literature it is not commonly recognized or diagnosed by most doctors
including some allergy specialists and many stomach specialists.
Various allergy sites include lists of the common foods associated
with certain pollens, dust mite or latex. However, a comprehensive
list that is easy to read or interpret can be difficult to find.
Also, the names of some of pollens or the common links between a
group of pollens and a group of foods can 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 experience near immediate burning sensation in your
mouth or throat with or without swelling. However, it is commonly
recognized that frequently in medicine, symptoms do not occur in the
“classic” or typical manner in a specific person. Worded another way
doctors are taught "patients don't read the textbooks". Therefore,
you may experience variations of the reaction such as throat swelling
or tightening, burning when swallowing, a lump in the throat or a
sense of swallowing difficulty but not make the connection to what
you ate or what is happening to you.
You or your doctor may misinterpret your symptoms.
Frequently people just assume it happened because they were having a
choking spell on food that was poorly chewed, swallowed too fast, or
eaten or drank while too hot or cold. Commonly, it is assumed that an
esophageal (swallowing tube) disorder, especially acid reflux with a
hiatal hernia is the cause. Acid reflux can cause an esophageal
constriction called a stricture or ring that can result in food
sticking sensation but this is usually associated with heartburn
symptoms or food getting stuck prompts an upper endoscopy or scope
exam. Other times, especially if occurring in an elderly person, a
neurological condition like stroke or Parkinson’s disease is blamed.
Sometimes doctors decide that your symptoms are due to a nervous
reaction or neurosis that historically was called as globus
hystericus. The hystericus portion of the term is usually dropped
these days to the shorter term globus or globus sensation especially
since it is not proven it is due to a psychiatric problem. However,
globus may be the diagnosis arrived at if your complaint is you feel
a lump in your throat and an ‘evaluation” appears to turn up nothing
even if OAS was not considered or excluded.
An unusual condition that has been more recently
recognized in the field of gastroenterology (diseases of the stomach
and intestines) that may be related to 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 teenage boys and young men who
presented food sticking episodes without heartburn or acid reflux
symptoms, it is associated with a strange appearance of the esophagus
on endoscopy (lighted scope exam of the upper gastrointestinal
tract). What the doctor doing the scope sees is your resembles a
cat’s esophagus. That is it looks like it has rings (cats have
cartilage rings in their esophagus, we do not) and this is referred
to as "ringed esophagus" or felinization of the esophagus. On biopsy
of such a ringed or felinized appearing esophagus (that is also often
narrowed resulting in food sticking) microscopic signs of allergy are
noted. The lining shows numerous eosinophils, a reddish pink
appearing white blood cell, characteristic of allergic conditions.
These eosinophils release chemicals like histamine that trigger
swelling, pain, and damage to tissue.
Food allergies are commonly found to present in EE
though sometimes the search for a food allergy by traditional skin
tests or IgE blood tests is negative. Treatment is avoidance of known
food allergens and swallowed nasal steroids sprays that are designed
for use in the nose for nasal allergies. Though not specifically
proven yet, eosinophilic esophagitis (EE) may be a variant of the
Eosinophilic gastroenteritis and eosinophilic or
allergic colitis also exist and can be diagnosed by biopsies of the
stomach, small intestine and colon respectively. Allergic colitis is
typically seen in infants who have cow’s milk protein allergy. It
presents as colic type abdominal pain, diarrhea, weight loss and
bloody diarrhea in an infant on cow’s milk formula or sometimes in
breast-fed infants whose mom is drinking a lot of cow’s milk.
Allergic gastroenteritis occurs in any age group
presenting typically 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 is detectable only by special stool
chemical tests known as fecal occult blood tests (FOBT) or stool
At least some people with food intolerance that does
not make sense on limited diet diary information, blood tests,
biopsies, or allergy testing, may have a form of OAS. In other words,
the presence of known pollen or latex allergy may be predisposing to
reactions to foods known to cross react with allergies noted in OAS.
However, instead of classic oral allergy syndrome symptoms other
stomach and intestinal symptoms or even non-gastrointetinal symptoms
Support of this concept can be found in detailed
screening of individuals for food intolerance. Those with known
pollen or latex allergies, any known food allergies or intolerance
including gluten intolerance (celiac disease) and casein intolerance,
are asked to complete a series of symptoms assessment and severity
rating scales followed by a strict elimination diet. This is followed
up by re-assessment of response of symptoms while re-introducing
foods one at a time while monitoring for recurrence.
This type of analysis is the basis for the Neopaleo
Specific Diet. In the near future online symptom assessment and
screen for food intolerance along with dietary recommendations
specific to individuals will be available at
www.thefooddoc.com. An online diet symptom diary
will also available. A simplified table illustrating the common foods
that may cross-react with the broad categories of pollen allergens
and latex allergy is available. Food intolerances are more commonly
being recognized as a common cause of illness and symptoms.
Individualized specific diet recommendations and elimination diet
trials may be more helpful in discovering any possible links to what
you are eating and how you feel.
Copyright 2006 The Food Doc, LLC. All rights
Dr. Scot Lewey is a physician who is trained and board
certified in the specialty of gastroenterology (diseases of the
digestive tract) and has a growing practice focused in the area of
food intolerances, especially gluten and cow's milk protein. He is a
published researcher and author and founder of an educational website
http://www.thefooddoc.com helping people with food
page Visit Mega