Common Allergy Tests Are They Conclusive?
Allergy symptoms can affect the quality of life, and yet allergy testing is frequently ignored in diagnosing allergic disease and treatment. More than 12 million North Americans suffer from food allergy
What is an allergy?
Allergy is a symptom caused by the interaction between an allergen and an antibody known as IgE (Immunoglobulin E). The severity of allergies varies from person to person and can range from minor irritation to anaphylaxis
What are some of The Symptoms of Allergies?
- Red and itchy skin
- Trouble breathing, speaking or swallowing
- A drop in blood pressure, rapid heartbeat or loss of consciousness
- Flushed face, hives or a rash
- Swelling of the eyes, face, lips, throat, and tongue
- Anxiousness, distress, faintness, paleness, weakness
- Cramps, diarrhea or vomiting
What is an Allergy Test?
It is an exam performed by an allergy specialist to find out if your body has an allergic reaction to ingested allergens such as foods like peanuts, contact allergens, these must come in contact with your skin such as poison ivy, or inhaled allergens, these affect the body through membranes of the nostrils or contact with the lungs such as pollen and mold. The medical history will also be included with questions about your diet, your family’s medical history, and your home and living area. Your doctor won’t just consider allergy test results when determining whether you have an allergy
Questions to Discuss with Your Doctor
If you suspect that you may have an allergy, talk to your doctor and ask following questions
- What is the cause of my symptoms?
- Should I have allergy testing done?
- What types of allergy testing should I have and why?
- Should I stop taking medications prior to testing?
- Are there any risks to allergy testing?
- Ask for a referral to a certified allergist
THE MOST COMMON ALLERGY TESTS
The skin test is performed by a tiny drop of liquid food extract for each suspected food, and is placed on the skin. The skin is then lightly scratched by a thin needle and within 20 minutes, a small bump with a little redness around it should appear if you are allergic to that food. SPT’s rarely produce false negatives but about 50 – 60 percent of SPT’s show false positive results. This happens because members of a food family frequently share similar proteins. Such as peanuts, the same members of legume family are green beans. If you are allergic to peanuts, the test may also show that you are allergic to green beans even though a green bean has never been an issue for you. If you are taking an antihistamine, it is important to know that they can interfere with the skin test. This means that you must stop using antihistamine medication for several days before the test
Allergy blood testing measures the amount of IgE antibodies (immunoglobulin E) in the blood. The higher the level of IgE, the more likely you are to have an allergy to that particular food. Antihistamines and other medications do not affect blood tests, they can also be done for people with skin conditions, young children, or if the doctor suspects you may have a severe reaction to a skin test he will recommend a blood test. Because of this, the blood testing is considered a safer option. The blood test can measure more than 600 allergens, such as common foods, pollens, grasses, weeds, occupational exposures and some medications. The blood test result takes several days to arrive
Food Elimination Diet
If your doctor suspects you have a food allergy, he may choose the food elimination diet, by temporarily eliminating specific foods from your diet. During this period you will avoid suspected foods and if your symptoms disappear the food you eliminated could be causing your allergy. During this time, your allergist will monitor your symptoms. At the end of this elimination diet, your allergist may introduce the problem food back into your diet. If your symptoms return, you are most likely allergic to this food. Most common food allergens are peanuts, tree nuts, sesame seeds, dairy, eggs (especially egg whites), fish, shellfish, soy, sulphites, wheat and mustard
Is There a Cure for Allergies?
According to the World Health Organization, Immunotherapy is the only allergy treatment that fights the underlying cause of allergies. Most allergies can’t be cured. Once you find out what you are allergic to, your allergist will recommend that you avoid known triggers. These may be foods, animals, cleaning products and simple lifestyle changes. He may also recommend immunotherapy and allergy shots.
Allergy testing can give false positives, even false negatives are possible. It is also important to know that neither skin testing nor blood testing can predict the severity of all potential allergic reaction. You should never eat any food that you are allergic to, not even a small amount. Overtime allergies can change, this is why it is recommended that you do a follow-up testing in a few months with your allergist.
For recipes that accommodate most diets click here >
This article is for informational purposes only, and is not meant to offer medical advice
American College of Allergy, Asthma, and Immunology
Canadian Society of Allergy and Clinical Immunology