This can help detect problems in the body associated with diseases.
A blood test is when a blood sample is taken for analysis in a laboratory. Doctors order blood tests to check glucose, hemoglobin, or white blood cell levels. This can help detect problems in the body associated with diseases. Sometimes blood tests can help determine how well a particular organ, such as the liver or kidneys, is working, and whether you have allergies. Below we will tell you in more detail what tests are needed to detect allergies.
1. What is an allergen-specific immunoglobulin E (IgE) test?
The allergen-specific immunoglobulin E (IgE) test measures the concentration of various IgE antibodies. Antibodies are produced by the immune system to protect the body from bacteria, viruses, and allergens. IgE antibodies are usually found in small amounts in the blood, but a high level of this type of antibody can be a sign of the body’s disproportionate response to certain allergens. IgE antibodies differ depending on the allergen to which they react. An allergen-specific immunoglobulin E test can show what the body is reacting to.
2. Why is the test being done?
An allergen-specific immunoglobulin E test is done to detect certain types of allergies. These include allergies to certain foods, animal dander, pollen, mold, certain medications, dust mites, latex, or insect venom.
3. How to prepare for the IgE test?
Your child can eat and drink normally, unless he needs another test at the same time as fasting. Tell your child’s doctor about all the medicines they take because some medicines can interfere with the test results.
4. How is the test?
In most blood tests, a blood sample is taken from a vein. To do this, the health worker:
- cleanse the skin;
- puts a rubber band around the area so that the veins swell with blood;
- inserts a needle into a vein (usually in the arm, either on the inside of the elbow or on the back of the arm);
- takes a blood sample and puts it into a vial or syringe.
5. Is the IgE test associated with any risk?
The IgE test is considered a safe procedure with minimal risks. Some children feel dizzy or faint when taking blood. Some children and teenagers are very afraid of needles. If your child is worried, talk to their doctor before the exam about ways to make the procedure easier.
There is often a slight bruising and/or mild muscle pain at the puncture site, which may last for several days. Seek medical attention if your child’s discomfort or discomfort gets worse or lasts longer. If you have any questions about the IgE test, talk to the doctor who will do the blood test.
6. Skin tests
Allergy skin tests are widely used to diagnose allergic conditions, including:
- allergic rhinitis (hay fever);
- allergic asthma;
- Dermatitis (eczema);
- food allergies;
- penicillin allergy;
- Allergy to bee venom.
Skin testing is generally safe for adults and children of all ages, including infants. However, skin testing is not recommended under certain circumstances.
Your doctor may advise against skin testing if:
- Have you ever had a serious allergic reaction. You may be so sensitive to some substances that even small amounts used in skin tests can cause a life-threatening reaction (anaphylaxis).
- You are taking medications that can affect test results. These include antihistamines, various antidepressants, and some heartburn medications. Your doctor may decide that it is better for you to continue taking these medicines rather than temporarily stop taking them in preparation for a skin test.
- You have certain skin conditions. If psoriasis or severe eczema affects large areas of the skin on the arms and back (areas where tests are usually done), there may not be enough free, unaffected skin to perform an effective test. Other skin conditions, such as dermographism, can make test results unreliable.
- Blood tests (in vitro tests for immunoglobulin E antibodies) may be helpful for those who should not or should not have skin tests. Blood tests are not used for allergies to penicillin.
In general, allergy skin testing is reliable in diagnosing allergy to airborne substances such as pollen, animal dander, and dust mites. Skin tests can help diagnose food allergies. However, because food allergies can be complex, you may need additional tests or procedures.