All you need to know about Allergy Testing
Allergy testing is offered to detect specific allergens. If you have allergies or suspect that you have an allergy, you already know that you need to figure out what your triggers are. That is where allergy test comes in. Of course, the path to relief is found by appropriate allergy testing that will reveal the cause of your discomfort.
However, one size does not fit all when it comes to allergy testing. Your doctor will work with you in order to determine which test is right for you. In my experience, knowing what to expect before going to a doctor’s visit always puts you at ease.
Here we will discuss in detail what you can expect at your doctor’s office, the allergy tests available in Singapore and what does each test entail.
What type of allergy test is ideal for me?
Your doctor will ask you questions in order to start building a case file. Before your visit, you are recommended to keep a diary of your symptoms that you believe may have been caused by an allergy. You will also be asked questions regarding your family history, lifestyle choices or any other areas of your life that may be related to your allergies.
This vital information that may help him to figure out the best allergy testing procedure for you. Furthermore, your doctor will explain to you all the pros and cons of each allergy test, ensuring you choose the best one that suits your preference and allergy condition.
The two main types of allergy tests – blood test and skin prick test. Depending on the information provided, your doctor will suggest the test that is best suited for your case, and explain each test option and its possible advantages and disadvantages.
What is an allergy blood test?
RAST blood test is a technique used to detect IgE antibodies produced against particular allergens. Today, there is a broad range of allergen panels that can be tested via IgE antibodies blood test.
The blood sample is obtained through a simple blood taking procedure and in general, your blood test results will take approximately 5-7 working days.
What is a Skin Prick Test?
This is a diagnostic tool that allows your doctor to effectively determine your trigger allergens. The tool consists of commercial-grade and standardized allergen extracts that cover a broad range of species-specific allergens including pet dander, foods, mold, dust mites, and pollen.
Though fairly less complex, the skin prick test is an effective way to detect allergies. It is mostly performed over the patient’s arm. This test checks for immediate allergic reactions to as many as over 40 different substances at once. In grownups, the test is usually performed on the forearm. On the other hand, children are usually tested on the upper back.
How is the skin prick test carried out?
During this test, your forearm is initially sterilized using alcohol before being marked out to specify the various testing zones for each allergen. A small drop of allergen is then inserted into the epidermis through a small puncture using a skin applicator. After about 20 minutes, the patient will be provided with the results.
Usually, patients will only experience mild itchiness and perhaps redness in the tested area. However, the symptoms usually subside within a few minutes.
Your doctor will thereafter review the tested area and check for any evidence of bumpy swelling, redness, and examine the extent of swelling if any. If you are sensitive to a certain allergen, you may experience swollen hives known as wheals at the spots where the culprit allergens were pricked.
Important things you need to know before your skin prick test:
- Some medicines such as antidepressants, cough syrup as well as steroidal-based medication can potentially affect the reaction to allergens during the skin prick test.
- It may be difficult to correctly interpret the results in patients suffering from chronic skin conditions in the tested area.
- If in any case, the skin prick test fails to correlate with your history, your doctor will have to confirm the results using the blood allergy IgE testing.
- The use of oral or topical antihistamines should be stopped for at least one week before the skin prick testing.
Generally, the skin prick test is a highly effective technique for determining potential culprit allergens. If you are currently having any allergy health issues, please speak to us. We will be more than happy to help you live a happy and fulfilling life free from allergies.
What is the RAST IgE blood test?
This is an allergy blood test. RAST stands for radio-allergo-sorbent test.
You can expect a blood sample to be taken from you to be tested for specific IgE antibodies that can reveal your potential allergy.
What are the benefits of the RAST IgE blood test?
- It can be safely used on children
- You can take this test without having to discontinue any medications that you are currently taking.
- There is no risk of an allergic reaction.
- Existing skin issues will not be exacerbated by an allergy blood test.
When is the RAST IgE blood test unsuitable?
The results can take about 5-7 days. This may not be suitable if you need to find out your allergic triggers sooner.
What is a Skin Prick test and what should I expect?
It is an allergy test that involves exposing your skin to various allergens such as pet dander, dust mites, food, pollen, and fungi. Don’t worry, these are standardized, commercial grade allergens and safe for use in allergy testing.
Your doctor will apply an allergen under a layer of your skin with a small lancet that is barely felt as the needle enters your skin with very minimal discomfort.
It is also known by other names like “Skin Scratch” or the “Puncture test”.
Is the skin prick test painful?
Allergy skin prick test is usually painless as it uses special micro needles that barely penetrate the surface of your skin. It involves the insertion of allergens into your skin through small lancets that safely penetrate the surface of your surface. The tested part of your skin is marked and pricked using small drops of various allergens. You won’t bleed or feel more than slight, mild momentary discomfort.
What are the potential side effects of skin prick test? Is it safe?
As we previously mentioned, skin prick test is a simple, safe yet effective allergy testing technique that doesn’t have any significant adverse effect. It is conducted in a hospital or clinic setting with close supervision from your healthcare professionals. Most patients tolerate the procedure quite well with minimal pain and without any incidence of bleeding.
However, some people may experience mild redness or itching in the tested area. It is also worth mentioning that a severe reaction to skin prick test is very rare. Generally, the skin prick test is not ideal for:
- Anyone with a history of anaphylaxis to certain allergens
- Anyone who is on an oral antihistamine and isn’t willing to stop before the skin prick test
- People with severe skin inflammatory health condition that affects a huge part of their skin such as psoriasis or eczema
Why should I choose to do a skin prick test?
- Skin prick test are more cost effective, as far as allergy testing goes.
- Your results can be obtained in the same day.
Is there anything I should be aware of when taking a skin prick test?
- There is a chance that you may have a severe reaction to one of the allergens introduced under the skin during the allergy testing.
- You may be required to stop taking any allergy medication that you are currently on.
In most cases, allergies can be diagnosed by these allergy tests. To understand more about your allergies, you can speak to your doctor for further information!
Are there any other skin allergy testing techniques?
There is another test called the skin patch test which may be used to test contact allergies due to substance or particles in your topical creams, drugs, fragrances, and cosmetics. When you visit our clinic, our doctor will explain to you in more details all you need to know about these allergy tests.
Do I have to stop my allergy medication or other long-term medication for allergy testing?
It has been proven that some allergy medications, including cetirizine, antihistamine like antihistamines like piriton and loratadine can potentially affect the results of the skin prick test. Antidepressants can also impact the results as well. This means that you will have to inform your doctor about all the medication you are currently using.
How fast can I get my allergy test result?
For an allergy blood test, you will need to wait for between one or two weeks before your results become ready after lab processing. On the other hand, the skin prick test only takes approximately 20 minutes.
What is the accuracy and reliability of an allergy test?
Skin prick tests, when performed appropriately, can be highly reliable and effective. However, there is a chance that you may have a negative skin prick test but still, develop an allergy at some point in life. This scenario is referred to as a false negative. It occurs due to:
- Doctor variability: skin prick test is presided over by healthcare professionals with an invariably slight deviation in their skills and techniques.
- Your body may experience a new allergy with time as a result of repetitive exposure to allergens.
- You may be using some medicinal drugs that lead to a false-negative result.
The allergy blood test has an advantage over the skin prick test in that your test results are not affected by the medication you might be using. Regardless, there is a possibility for a false positive, which may result in unwanted anxiety and confusion among patients.
How regularly should I consider allergy testing?
This may vary from one individual to another, mainly depending on the new onset of allergy symptoms. It also depends on your exposure to new allergen triggers.
Does insurance covers for allergy tests?
Kindly consult your insurance firm to confirm whether you are covered for your test.