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How To Read Allergy Test Results Numbers

Are There Any Risks To The Test


There is very little risk to having allergy skin tests. The test itself is not painful. The most common side effect is red, itchy skin at the test sites. In very rare cases, an allergy skin test may cause anaphylactic shock. This is why skin tests need to be done in a providers office where emergency equipment is available. If youve had a patch test and feel intense itching or pain under the patches once you are home, remove the patches and call your provider.

Study Design And Patients Characteristics

This study included a total of 172 children . All patients underwent a SPT with cashew nut extract and a DBPCFC test with cashew nut. The mean age of the children was 8.8 years , with 102 boys and 70 girls . Symptoms consistent with eczema were reported by 65 children , with asthma by 52 children and with hay fever by 89 children . Medical ethical approval was obtained and all patients signed informed consent.

Pros And Cons Of Allergy Blood Tests

Advantages of allergy blood tests include:

  • Can be done at any time, regardless of any you are taking
  • Requires only one needle stick this may be more attractive for people who are afraid of needles. Allergy blood testing is the preferred test for infants and very young children.

Disadvantages of allergy blood tests include:

  • More expensive than skin testing many health insurers do not cover allergy blood tests.
  • May be less sensitive than skin tests
  • Takes days or weeks to get results because the blood sample must be sent to a laboratory for evaluation skin testing provides immediate results.

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What Causes A Food Allergy

Food allergies are one of the most common forms of allergy that affect 85% of people including children as well as adults. An IgG food allergy test can help detect food allergies. The symptoms of food allergy are usually seen in babies and children, and they grow with time. Sometimes they outgrow at times as well. A food allergy even develops with time forfood that you have eaten for years. There are certain kinds of food that usually contribute mostly to food allergies like

  • Eggs
  • Certain kinds of seeds like mustard and sesame seeds

What Is A Positive Skin Test Result

Intradermal Skin Tests  Allergy Dog Central

A positive skin test involves the formation of a bump and redness . In addition to the allergens in question, skin testing is also performed with a positive control that should always cause a skin reaction, and a negative control, , that should not cause a reaction. A test is positive if the allergen causes a wheal 3 mm greater than the negative control, and if the skin has a response to the histamine, as well. It is important to know that individuals cannot undergo skin testing if they are using antihistamines, since this blocks the histamine-mediated reaction.

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How Do I Interpret Allergy Test Results

by Health Professional

Recently a reader posted this question here at, saying that her child had results like this: Trees 2++ Grass 4++++. She wanted to know what the numbers mean.

First, let me say that interpreting allergy test results is a tricky business. These tests are notorious for their false positives. That means that the test indicates you are allergic to something, but in fact, you are not. That can definitely be confusing for all concerned

Types of Allergy TestsAlso, not all allergy tests are the same, so their results differ as well. The traditional type of allergy test is a skin test or scratch test. This kind of test has been around for decades.

It involves placing a drop of liquid consisting of a possible allergen, such as cat dander, on the skin. Then, the allergist scratches or pr.icks the skin to enable the solution to enter the skin.

If a red, raised itchy area called a wheal develops at the spot, it’s a good sign that you may be allergic to that allergen. This is called a positive reaction.

Two other types of skin tests may also be done:

  • Intradermal test, where the allergen solution is actually injected into the skin often used to followup scratch testing.It’s more sensitive, but also produces more false-positives.

  • Skin patch test, where a pad impregnated with the allergen solution is taped to your skin for a day or two.

But generally, the higher the number, the more sensitive you are to that particular allergen.

Igg Food Allergy Test Accuracy Results Interpretation And Benefits

An allergy is usually known to occur when the natural defense mechanism of the body react to exposure of a certain foreign substance and tries to evacuate the same by sending out chemicals to defense against the foreign element. All people are known to have some or the other kind of allergy be it from dust, pollutants, food as well as any other substance.

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There Are Two Main Types Of Allergen Skin Testing Used To Help In The Evaluation Of Potential Allergies Skin Prick Testing And Intradermal Testing

Skin prick testing is minimally invasive and involves pricking the outer surface of the skin with either a commercial allergen extract or the fresh allergen if needed. Intradermal testing is slightly more invasive and involves a small injection of a solution containing allergen that is placed just underneath the surface of the skin.

These skin tests are done on areas of the body that generally contain a substantial number of allergy cells, such as the arm or the back, and they are read for results during your appointment about 15-20 minutes after being placed. At Allergenuity Health, we attempt to be as least invasive as possible while getting the information we need to best help you with your goals.

Why Seek An Allergist

Interpreting Allergy Test Results

Attempting to self-diagnose food allergies and interpreting results can be challenging. With food allergy tests, false positives and false negatives can occur. For this reason, you should always seek out a board-certified allergist to diagnose and treat your symptoms. Moreover, laboratories use various blood tests with different scoring systems. An allergist, however, is an expert and will be aware of the differences and know how to accurately interpret the results and explain to you what the results mean.

Food allergy testing is an important part of making a diagnosis. However, an allergist has many tools that increase the accuracy of a diagnosis, such as taking into account your medical history, using the elimination diet, and using other methods of food allergy testing .

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What Happens During The Apt

  • First, we will use a special tape to place a prepared panel of food extracts on your back.
  • You will be required to keep this panel dry, and in place on your back, for 48 to 72 hours.
  • We will schedule a return appointment in our clinic so your allergist can remove the panel and obtain the test results.

The Ige Test Explained: Screening For Food Allergies

Immunoglobulin E is a type of antibody carried by humans and other mammals. It figures prominently in immunity responses and plays a pivotal role in allergic conditions like food allergy and anaphylactic shock. The antibody binds with the antigen. Mast cells then release histamine, and the allergic response occurs.

IgE Levels Read the Number of Antibodies in the Blood

An IgE test measures the blood level of the antibodies, a family of proteins referred to as gamma globulins. Antibodies are important weapons used by the immune system to detect and respond to the invasion of foreign substances like bacteria, viruses, and allergens.

IgE Triggers Allergic Responses

IgE is the primary mediator that stimulates the release of inflammatory agents in mast cells, such as histamine and leukotrienes. IgE also triggers the most devastating of allergic reactions, like anaphylactic shock.

Tests Need to be Interpreted by a Medical Professional

The IgE test may be done to screen for allergies. It is performed by taking a blood sample, which is sent to a lab for testing. The results are processed in a few days. An IgE test will tell you to what degree the body reacts to various types of food or particles and other allergies. A low score does not necessarily mean that a food is safe, but a high score definitely means there is a problem. An unusually low level can actually indicate a rare autoimmune disorder.

Low, Normal and High IgE Levels

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What Is A Type I Hypersensitivity Reaction

Following exposure and re-exposure to an antigen in susceptible individuals, a type I, or immediate, allergic reaction involves antigen-presenting cells, the activation of T-helper cells, the stimulation of B cells that release specific IgE, and the release of various pharmacological mediators from mast cells and basophils. The release of the mediators causes symptoms such as sneezing, wheezing, and weals.

Type 1 IgE-mediated hypersensitivity reaction pathway

Credit: Gaurab Karki, Microbiologist Kathmandu, via Online Biology Notes.

What Is Allergy Skin Testing


Skin testing is the most reliable form of allergy testing. Because mast cells are located in high numbers just under the skin, results of skin testing have proven to be more accurate than blood testing in diagnosing allergies.

Please bring with you a complete list of all medications, as well as your pharmacy number and street address. We routinely send prescriptions electronically and need your pharmacy information to ensure accuracy.

Your initial visit will take 2-3 hours in total. During the testing process, we will use a marking pen on your back and arms, which may cause staining on a shirt. For this reason, we suggest you bring an older shirt with you to wear home.

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There Is A Risk Present For A False Positive Result

Not only will some patients naturally test negative on the gluten intolerance blood test, certain co-existing medical conditions can create false results. People with liver disease, Type 1 diabetes mellitus, rheumatoid arthritis, or certain heart conditions can also test have negative test results on the first gluten intolerance blood test.

Thats why there are 3 additional tests which may be ordered and then compared with the first initial results to help come up with a diagnosis.

The EMA blood test looks for specific antibodies that are created when gluten is consumed as well. The specificity of this test is nearly 100%, although up to 10% of people who do have Celiac disease will have a negative test result. This gluten intolerance blood test is usually reserved for those who have a difficult diagnosis because it is relatively expensive and requires cord blood to complete.

The IgA total serum blood test is a second option when trying to screen out the possibility of Celiac disease. When Celiac disease is present in the body, it may naturally produce a false negative on the EMA blood test because of an IgA deficiency. This test can determine if that deficiency is present. If it is, then a third and final blood test may be ordered.

The DGP IgA or IgG blood test is used as a further screen to test for antibodies. The results of these tests will then be compared to each other in order to determine if there is the possibility of Celiac disease present.

How Long Does An Allergy Skin Test Take

A person has to stay with the patch on their forearm or their backs for a period of 48 hours. This is for the patch allergy skin test. For the skin injection allergy skin test, the test is given fifteen minutes then observed for any allergic signs.

  • Allergy skin test list of allergens which are main or primary include allergens that are mostly inhaled. These affect the lungs or membranes found in the nostrils or throat, an example is a Pollen.
  • The second primary type is one that has to be ingested. They are known as ingested allergens and they are found in some foods e.g peanuts, soy, and seafood.
  • The third example is the ones that cause allergies by having to come into contact with a persons skin. They mostly lead to itchiness and rashes. Such allergen is the poison ivy

Allergy skin test results numbers are the numbers against which the results of the test are compared to in order to give the correct diagnosis.

Allergy skin tests should be done by specialists only to prevent the side effects from being extreme and life-threatening. The tests are useful in determining the allergens that are harmful to a particular individual.

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What The Rast Shows

A negative RAST is as reliable as a negative SPT in ruling out a true food allergy. However, RAST has a slightly higher false positive rate than SPT, making it less reliable for confirming an allergy. If you have been diagnosed with a true food allergy, RAST can be useful in monitoring IgE values. If your RAST level falls below a given point, your allergist may recommend an Oral Food Challenge in our clinic, to determine if you still have an allergy.

Rast Score How To Read Them

Comprehensive Food Panel Results explained – Food Allergy Testing Results

pMy son’s allergist basically tells me nothing. Which tells me it’s time to find a new allergist. Anyway . . . /ppMy son had the RAST test done, not the CAP RAST. Everyone seems to talk about the Cap Rast. Is it better?/ppMy son’s Rast scores were:/ppPeanut 1.07 KU/Lbr /

4-being severely allergic 3-2% change of outgrowning2-75% change of outgrowing it1-80% change of outgrowing it.If your son is a 1 you are so lucky! BUT if you read my other post they also say there are negative positives! Scarey. As far as I know the CAP-RAST test is more accurate. It measures to what degree the child is allergic. So if you want to have him tested in 2 yrs, it will tell if he is outgrowing it our not. In my case my son tested 22.3 KU/L.!! So I don’t need a CAP test. I know it is severe, but in you case if might be different.Good luck!

4-being severely allergic 3-2% change of outgrowning2-75% change of outgrowing it1-80% change of outgrowing it.If your son is a 1 you are so luckyI think perhaps you misunderstood the original poster — her son’s test score wasn’t a Class 1, but a measurement of 1.07 KU/L. If I recall correctly , the original poster’s son’s score of 1.07 KU/L would be a Class III, which is on the low end of “moderate”. Do you know where your allergist got those numbers about the possibility of outgrowing the allergy? I haven’t seen them before, and they seem so optimistic, I’d love to see them from the source before I get my hopes up too much. Thanks.

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How Do I Know If I Need An Allergy Test

If youre allergic to allergens in the air like dust, pollen or pet dander, you may develop allergic rhinitis. Also known as hay fever, this allergic reaction causes:

Food allergy symptoms typically occur within 30 minutes of food ingestion but may occur up to two hours after ingestion. People with food allergies may experience:

  • Skin symptoms such as hives, swelling of the face, lips or tongue, generalized itching.
  • Respiratory symptoms such as coughing, wheezing, shortness of breath, chest or throat tightness.
  • GI symptoms such as nausea and vomiting, abdominal pain and cramps, vomiting and diarrhea.
  • Cardiovascular symptoms such as pale skin, weak pulse, dizziness or lightheadedness.

People who are allergic to latex, fragrances or metals like may develop contact dermatitis. This allergic reaction affects your skin. You may have:

  • Burning sensation on skin or .
  • Skin rash or itchy skin.

A patch test, performed by a dermatologist, is used to diagnose these types of reactions.

How Accurate Are The Food Sensitivity Test Results

The laboratories that process Everlywell Food Sensitivity tests are CLIA-certified and CAP-accredited laboratories. All of these labs perform frequent internal quality checks and testing, as well as regular inspections and validation of the accuracy of the testing they perform, and all of the at-home sample collection testing we offer customers has been thoroughly validated against traditional testing conducted in doctors offices and clinics.

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Why Allergy Blood Tests Are Done

Allergy skin testing is the preferred method, but in some cases blood testing may be ordered.

Allergy blood testing is recommended if you:

  • Are using a medicine known to interfere with test results and cannot stop taking it for a few days this would include antihistamines, steroids, and certain antidepressants.
  • Cannot tolerate the many needle scratches required for skin testing
  • Have an unstable heart condition
  • Have poorly controlled asthma
  • Have severe eczema, dermatitis, psoriasis, or another severe skin condition
  • Might have an extreme reaction during skin testing or have a history of life-threatening allergic reaction called anaphylaxis

Your doctor may also order blood testing to determine how well your allergy treatments are working. Blood testing may also show whether you have outgrown an allergy.

What Do The Results Of An Allergy Test Mean

Canine Allergy Blood Testing: Jasmine

Allergy test results may be:

  • Negative: You arent allergic to that substance. Its rare to get a false negative allergy test result .
  • Positive: Youre allergic to that substance. Note that even when tests correctly show that you have an allergy, it doesnt necessarily mean that youll react to that allergen. A false positive test result is possible, especially from a blood test. A false positive means the results show you have an allergy when you dont.

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