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The Real Deal on Food Allergy Testing

food allergy testing information

The proof is in the eating!

Food allergy is a clinical diagnosis. It is not a laboratory or skin testing diagnosis. The proof is in the eating, not the testing. Skin tests and lab tests are based on probabilities, not absolute certainties.

Lab Tests

IgE (the allergic antibody) grades and classes (Class 1, Class 2, Class 3, etc.) and terms like low, mild, moderate and severe are arbitrary and may vary from one laboratory to another. Pentucket Medical Allergy does not use such subjective grades or classes.

IgE is measured in Ku/Liter, or “units”.

IgE levels that indicate a 95% chance of an allergic reaction are:

  • Egg White 7 units 2 units if under two years old
  • Peanut 14 units
  • Milk 15 units 5 units if under two years old
  • Soy 30 units
  • Tree Nuts 15 units
  • Fish 20 units
  • Wheat 26 units

IgG is not an allergic antibody. Therefore, allergy testing with IgG is meaningless.

Skin Tests

95% chance of allergic reactions:

  • Egg 7mm or larger
  • Peanut 8mm or larger
  • Milk 8mm or larger

BE AWARE of Unacceptable Food Allergy Tests!

Testing predicts the likelihood of a reaction, not the severity. Testing can and often is falsely positive. For this reason, patients should not generally be tested for foods that they tolerate or that they have never previously eaten.

One form of food allergy skin testing, called the intradermal test, is not recommended by the American Academy of Allergy because of extremely high false positive rates and risk of reactions to the testing itself. If your allergist suggests intradermal testing for food allergies, you should seek a second opinion.

Food allergy testing cannot help with food intolerances, such as lactose intolerance. Intolerance is an unpleasant reaction to food that is NOT caused by an allergic reaction.

Remember, a patient isn’t diagnosed with a food allergy just because of a positive skin or laboratory test. If a patient is able to eat a food with no symptoms or reactions before testing, they can eat the food after testing.


Get more information, office hours and locations, and meet the Pentucket Medical Allergy team on our website!

Asthma: An Overview

what is asthma

Asthma is a condition that affects your lungs. The important thing to remember is that the condition is reversible with proper medications. Common symptoms that occur during an asthma episode are:

  • coughing
  • wheezing
  • shortness of breath
  • chest tightness

Not everyone with asthma presents the same way. Your Allergist can monitor your lung function and prescribe the right regimen of medications so that your quality of life is not affected.

What are Asthma Triggers?

The word “trigger” refers to things in our environment that cause an asthma episode. Some people with asthma have allergies as a main trigger. Environmental allergies can include:

  • tree pollen
  • grass pollen
  • weed and ragweed pollen
  • cats
  • dogs
  • feathers
  • molds
  • dust mites

An Allergist can perform skin testing to determine which allergens are triggers for you. Other triggers include:

  • colds and other viruses
  • the weather
  • exercise

These triggers can be properly managed so that they do not cause as much of a problem for people with asthma.

Tips to Effectively Manage your Asthma

The good news is that asthma, when taken care of properly, is very manageable. You should always keep your appointments with your Clinician (Allergist or Primary Care Provider). Information collected during these visits will guide your treatment and keep you on the least amount of medication necessary to control your condition. Always make sure you are taking your medication correctly! Asthma is controlled by using inhalers. There are different types of inhalers and the different types require different techniques. Always check and clean your devices. Make sure your medications are not expired. Always ask questions at your appointments to make sure you understand your treatment. Your Allergist and staff team are there to keep you breathing and healthy!



Wheat allergy and gluten intolerance- Are they the same thing?

The short answer is no.

When someone is allergic to wheat, they may develop symptoms of an itchy mouth immediately after eating. The itchy mouth may be followed by lip swelling, tongue swelling, and hives. This allergic reaction could also be associated with nausea and vomiting. These symptoms will occur within seconds to minutes after consuming wheat. Symptoms generally occur every time wheat is consumed. In reality, wheat allergy is relatively uncommon in adults. Children with wheat allergy usually outgrow this allergy by the age of 5 years.

Gluten intolerance manifests itself in a completely different way. Symptoms of gluten intolerance are often nonspecific. People may develop bloating and loose stools after consuming foods that contain gluten. However, symptoms may not occur immediately after eating gluten. The intolerance may be present for months or years before one realizes there is something wrong. The more specific name for gluten intolerance is Celiac disease. When people with Celiac disease consume gluten, an immune response occurs in the small intestine. This response results in the loss of absorptive capacity of the intestine. People with gluten intolerance may have weight loss and nutrition deficiencies due to the loss of intestinal absorptive capacity. A chronic itchy, bumpy rash may also occur on the extensor surface of the elbows, knees, and buttocks. The most noticeable symptoms are often flatulence and loose, fatty stools.

How are these disorders diagnosed?

Wheat allergy is diagnosed by an allergist after a careful history is taken. An allergist may perform skin or blood tests to confirm a suspected diagnosis.

Gluten intolerance is best diagnosed by a gastrointestinal specialist. This specialist looks for characteristic loss of absorptive properties in the small intestine. Blood tests and genetic studies may also be performed to support the diagnosis.

What happens when the diagnosis is confirmed?

Patients with wheat allergy must avoid consumption of wheat. However, other grains are often tolerated. Patients should carry an epinephrine pen in the event that a severe allergic reaction occurs. Wheat allergy is often outgrown, so regular follow-up visits with the allergist can assess for resolution of this allergy.

Patients with gluten intolerance must avoid gluten indefinitely. These foods include wheat, rye and barley. A gluten-free diet must be strictly followed to allow the return of normal intestinal functioning. The prognosis is good as long as a life-long gluten-free diet is followed.