What is a Food Allergy?

“My son is allergic to dairy too, so we have to buy lactose-free milk.”  You’ve probably heard someone say something similar to this if you’ve discussed food allergies with your friends or neighbors.  Food allergies are not widely understood and are often confused with food intolerances or other digestive problems.

A food allergy involves the immune system.  A reaction occurs when the body mistakes a particular food protein as harmful.  For allergies involving the IgE antibodies, the IgE antibodies attach themselves to the protein, as they would if it were a bacteria or virus, identifying the protein as harmful to the body.  The immune cells, or mast cells, then respond by releasing a chemical in the bloodstream called histamine.  The histamine released into the blood causes the symptoms we observe in an allergic reaction, like hives, swelling, itching, or restricted breathing. 

A food allergy is not the same as a food intolerance.  Food intolerances are generally associated with the digestive track and often are a result of an individual missing a certain chemical or enzyme used to digest a particular food.  For example someone who is lactose intolerant is missing an enzyme that breaks down lactose, a sugar found in milk.  However, food intolerances can also cause many similar symptoms to a food allergy, including hives or rashes.  While the difference between the two disorders may not be easily distinguished by symptoms, a doctor can determine whether a true food allergy exists.  

The reason it is important to know this difference is because a food allergy can be life-threatening, while a food intolerance is not.

Resources and References:

 Guidelines for Patients with Food Allergies

Wikipedia: Food Allergy 

Kids Health: Food Allergies 

Wikipedia: Food Intollerance 

About Histamine 

What to Expect at the Allergist

When we went to visit the allergist I had some unrealistic expectations.  I expected to have our son tested and to receive both confirmation of his allergies as well as numbers indicating how severe his allergies were, maybe even on a scale of 1-10 (e.g. 0= no reaction, 5= hives, 10 = anaphylaxis).  How little did I know!  Here’s a little information about what you need to know when you visit your allergist.

A large part of making an allergy diagnosis is your child’s medical history.  If you are seeing the allergist for the first time about what you believe is a food allergy, collect as many details as possible before you go.  What are the details of the symptoms and the timing related to what foods were consumed or contacted?  Keeping a food diary of what your child has eaten and what symptoms were experienced is very helpful.

Along with the history you bring, the allergist will likely perform one or more allergy tests.  There are three types of tests that are performed to determine the existence of a food allergy.

• Skin Prick
• Blood Test
• Food Challenge

For a skin prick test, a drop of the substance being tested is placed on the patient and the skin is pricked, allowing some of the suspected allergen to enter under the skin.  The doctor allows some time to lapse, usually about 15 minutes, and if hives occur around the prick, then the patient may possibly be allergic to that substance.  The procedure is not usually painful, although it may be uncomfortable.  This test is used to measure a protein called IgE that is involved in many types of food-specific allergic reactions.

A blood test (CAP-RAST) involves a blood draw which is sent to a laboratory where tests are done to determine whether the patient has IgE antibodies to specific foods.  The test is compared to “predictive values” for specific foods, and if the amount of IgE antibodies is higher for that food, then the patient has a very high chance  (95%) of having an allergic reaction to that particular food.  This test does not, however, detect non-IgE allergies.  The test results are not available immediately, but are usually completed in about a week.

A food challenge is the gold standard for diagnosing food allergies.  This is a definitive test to determine whether a patient will have an allergic reaction to a food, but does carry the risk of serious reactions.  This test is conducted by giving the patient the allergen in a capsule and observing the reaction.  This is done under a doctor’s supervision and should only be performed by trained personnel.  This test is also helpful in diagnosing non-IgE allergies.

Tests for food allergies are not straightforward or easy to interpret.  Skin tests may give false positives, and blood tests are not definitive in whether a patient will react to a substance or how severe the reaction may be.  Your allergist will interpret the test results in conjunction with your medical history and decide what is the best diagnosis and course of action.

If you are like many of us, you walk away with your head spinning, trying to wrap your mind around what this means for the child you are responsible for keeping safe.  Every person’s allergies and potential reactions are different.  There is no quick answer.  Find a good allergist and work closely with him or her to come up with a course of action that you feel good about.  Schedule regular visits, based on your needs.  There is a lot of information available about food allergies, but be sure you get it from reliable sources, and if there’s ever a question, consult your allergist.

References:

Food Allergy Diagnosis (Wikipedia)

Food Allergy And Anaphylaxis FAQ and PDF on Testing

Choosing an Allergist

Not all allergists are created equal!  I thought every allergist would be an expert in all types of allergies, including food allergies, but that is not the case.  Allergists specialize in the diagnosis and treatment of allergic diseases, asthma and diseases of the immune system.  This can range anywhere from eczema to seasonal allergies to chronic sinus infections.  Before you assume that your allergist knows how to give you adequate guidance about your child’s food allergies, be sure to do a little leg work of your own.  If you don’t do your homework you might have an experience like ours.

The first allergist we visited didn’t bother test our son for eggs or dairy because he felt my description of his reaction was sufficient enough to diagnose him with a food allergy.  He simply suggested we take a skin test to see if he was allergic to any nuts, which our son was.  When I asked the allergist what I should from that point, he simply said, “avoid the food he’s allergic to.”  That was all the information he gave us and I didn’t know what to ask.  I walked out feeling even more overwhelmed, lost and confused than I was when I came in.

A few things you can do to find an allergist who has experience with food allergies:

• Ask your doctor if they can give you a name of someone who has a lot of experience in this area (they may not know this information immediately but might be able to find out for you)
• Find out if the allergist is Board Certified (meaning they are up to date with all of the new research)
  
• Call the recommended allergist and speak to someone in the office who can tell you of the allergist’s experience with food allergies
  
• Talk to someone who has food allergies and already has an allergist they like
  
• Find an allergy support group in your area and ask the leaders or members of the group what their opinions are of the local allergists (click here for Your Local Food Allergy Support Groups )

After seeing three allergists, I wish I had the right information the first time.  I think the most valuable recommendations came from other parents of children with food allergies who had good experiences with a particular allergist.  If you don’t know someone, it’s worth visiting or reaching out to a support group that can help you get that information.  Finding a good allergist means not only getting the right tests, but also getting the information you need to manage the allergies.  With research constantly revealing new information, and recommendations for management frequently changing, it is worth finding and staying in contact with someone you can trust.

Does Your Doctor Have The Right Information About Food Allergies?

When we first took our son to the doctor about what we believed was a milk allergy, the doctor said, “Yup, sounds like a milk allergy, maybe you should try Gentle Ease Formula.”  When I looked at the sample they gave me, I saw it was a milk-based formula for gassy babies. I knew right then I wasn’t going to get any help from that pediatrician. 

We did our best managing his allergy until we had another allergic reaction, this time to eggs.  We knew we had to find another doctor.  The next pediatrician knew a little more than the first, and at least he knew enough to recommend that we see an allergist.

Many doctors are not sufficiently informed about food allergies.  There are many other illnesses that can present the same symptoms a food allergy does.  The National Institute of Allergy and Infectious Diseases recently funded and coordinated standardized guidelines for the diagnoses and management of food allergies based on the concern that practitioners were not all using the same information or methodology.

“Food allergy practice parameters in the past were written by allergists for allergists. There was a concern that other healthcare providers who were seeing patients with food allergies, such as family doctors, emergency room physicians, pulmonologists, dermatologists, and gastroenterologists, were using different definitions for food allergy and, as a result, managing the condition in different ways or even missing the diagnosis.”(MedscapeMedical News: New Food Allergy Guidelines to Debut December 6, Fran Lowry)

These guidelines were introduced in December 2010 and were made available to all healthcare providers.  It is still fairly new, and it is highly likely that your doctor has not yet read or is not aware of these food allergy guidelines.

If you feel you need to see an allergist, don’t hesitate to request a recommendation.  Your healthcare provider may not have all of the information he or she needs to adequately diagnose or manage the problem. 

If you would like to share these food allergy guidelines with your practitioner, follow the link below:

Guidelines for the Diagnosis and Management of food Allergyin the United States:Report of the NIAID-Sponsored Expert Panel

 

Discovering Food Allergies

Let's start at the very beginning of the food allergy discovery.  You have just had an experience (or maybe multiple experiences) that leads you to believe your child may be having an allergic reaction to something he or she has eaten. It was likely one or more of the following common symptoms of a food allergy:

• Hives (red or white, and usually itchy bumps on the skin)
• Nausea or vomiting
• Stomach pain
• Diarrhea
• Itchy skin or eczema
• Tingling or itching in the mouth
• Shortness of breath, wheezing, nasal congestion or other difficulty breathing
• Chest pain
• Swelling of lips, face, tongue, throat or other parts of the body
• Dizziness, lightheadedness or fainting
• Pale skin
• Anaphylaxis (constriction of airways, swollen throat, shock, drop in blood pressure, rapid pulse, dizziness or loss of consciousness, usually affects several areas of the body – requires immediate medical attention)

If your child has experienced some of the above symptoms and you are suspicious that it might be a food allergy, it might be a good idea to schedule an appointment with your doctor.  In the case of a severe reaction, don’t wait for an appointment with the doctor, seek immediate medical attention. 

Discovering a food allergy can be quite alarming.  A reaction can occur within minutes or up to two hours after eating or coming in contact with an offending food.  It can be a fairly mild reaction, causing discomfort and irritation, or it can be a severe and even life-threatening experience.

Our food allergy discovery occurred in 2007 when I stopped nursing our 7 month old baby.  He vehemently refused to take any milk-based brand of formula we offered, but cried out with hunger.  One day when trying yet another brand of formula, we accidentally spilled some of it on his cheek.  Within minutes, everywhere the milk had touched his skin was inflamed with red and white hives.  We immediately switched to a soy based formula and he gulped down the formula with no problems at all.  We later came to realize that the severe eczema he had all over his face and head were likely caused by the dairy I was eating when I was nursing him. Once we removed the food he was allergic to, his itchy skin and oozing sores healed and he had a healthy glow again.  That was our initial introduction to food allergies, and thankfully it wasn’t a life threatening experience.  Everyone is always curious about how we found out, and I’m sure others would like to know your experience as well.

What’s your story?  Where did your allergy discovery begin?

References:

http://www.mayoclinic.com/health/food-allergy/DS00082/DSECTION=symptoms

http://kidshealth.org/kid/ill_injure/sick/food_allergies.html#

Welcome to Eat Allergy Free's new Blog!

EatAllergyFree.com is a website my husband and I created to help share recipes and information with other families who are also dealing with food allergies.  When our son was diagnosed with allergies to dairy, eggs, and several types of nuts, we felt there was little we would be able to eat as a family.   It's been a few years now and we have learned to overcome many challenges, but we still vividly remember what it was like to be thrown into an unwanted diet and lifestyle so abruptly.  I want to share what I've learned with you, so your adjustment might be a little easier than ours was.  Please stay tuned for information about avoiding dairy, eggs and nuts.  Visit our site eatallergyfree.com if you want to share a recipe with others that is free of one or more of the top 8 allergens or if you are looking for more information about how to eat allergy free.