What Are Common Causes of Allergy?
The most common airborne causes of allergic reactions include:
Pollen
Pet dander
Mold
Dust mites
Many people are also allergic to:1
- Certain types of food (nuts, shellfish, soy, milk)
- Insects and insect bites (insect droppings, bee stings)
- Household chemicals (detergents, disinfectants, hair dye)
- Clothes or materials made of polyester, nylon, spandex, rayon, or rubber
Which Allergies Can You Get Tested For?2
Allergy testing can determine if you have the following allergies:
- Hay fever (allergic rhinitis ) or allergic asthma due to airborne allergens like dust mites , pollen , mold , or pet dander
- Dermatitis or eczema, which may be caused by airborne allergens, food, or contact with certain substances
- Food allergy caused by nuts, shellfish, soy, milk, etc.
- Penicillin allergy from medicine
- Bee venom allergy or other allergies to insect bites and venom
How Does Allergy Testing Work?3
Typically, allergy tests are conducted by introducing small amounts of allergens into your skin, and then monitoring for a reaction.
The allergens used in the test are proteins that come from different substances or species that trigger allergies. You’ll be able to tell not only if you’re allergic to pet dander, but whether you’re allergic specifically to dogs or to cats. Substances you’re allergic to will cause red bumps or irritation on the skin. The larger the bumps or the more intense the reaction, the more allergic you are to this substance.3
Before a test, your doctor may ask you to stop taking over-the-counter antihistamines, as they can lessen your reaction to the allergens. It is also recommended for you to jot down relevant details about your family’s medical history, lifestyle, and potential triggers before your appointment. This will help you and your doctor understand your symptoms and their possible causes better.
Types of Allergy Testing
Allergy Skin Tests
Skin tests have been proven successful for more than 100 years and can quickly produce results during your visit.4
During an allergy skin test, your skin will be marked with a pen to identify each substance being tested. A drop of each allergen is placed on the pen mark on your skin and then pricked (or injected). Allergists usually test the skin on your forearms or back5:
- PRICK TEST
The “prick test” or “scratch test” is the most common procedure. It can test your reaction to 50 different allergens. During this test, droplets containing a diluted allergen will be applied onto the skin. The surface of the skin is then pricked or scratched, allowing the allergens to enter and be absorbed into the skin. - INTRADERMAL TEST
An intradermal skin test is similar to the prick test, but uses a thin needle to inject the diluted allergen into the outer layer of the skin, called the epidermis. - PATCH TEST
A patch test uses patches or bandages containing the common allergens that cause contact dermatitis . You'll have to wear the patch or bandage for 48 to 96 hours before returning to your provider to determine results.6 Your provider will check if the patch or bandage caused reactions like redness, rash, or swelling on the skin.
Allergy Blood Tests
In some cases, a doctor may draw blood and send it to a laboratory rather than conduct a skin test. However, blood tests are not as common – they can result in false positives, take longer, and cost more. It is usually considered for patients who cannot discontinue allergy medicine; patients with skin conditions that bar them from safely undertaking skin tests, or conditions that may interfere with skin test results; and patients who may suffer from severe symptoms or medical complications upon exposure to allergens.
What are the Risks in Allergy Testing?
While most allergy tests involve pricking the skin, this should cause only a slight discomfort, and it is far less invasive than getting a shot. Allergy symptoms that arise out of a prick test or intradermal test typically go away within 1-2 hours. There is little to no chance of anaphylactic shock in healthy patients. 7
When Should You Get an Allergy Test?
Watch out for these symptoms. Book an appointment for an allergy test if these symptoms persist for more than a week or two, and especially if they keep coming back.
- Constant sneezing
- Itchy, runny, or blocked nose
- Itchy, red, or watery eyes
- Itchy, irritated throat
- Tightness in the chest
- Coughing or wheezing
- Sinus pain or pressure
Where Can You Book an Allergy Test?
There are many public and private clinics, hospitals, where you can get an allergy test in Singapore. It is best to call your long-time doctor or your primary care provider first to inquire if they can provide you the test, or to request for a referral or a recommendation to an allergy specialist.
Preparing for Your Allergy Test
It’s important to log your allergy symptoms before visiting the allergist. Additionally, disclose all of your medications to your allergist and discuss when you may need to discontinue the medication you’re taking prior to your test. Many doctors recommend discontinuing antihistamines three days to a week before a test for more accurate results
What’s Next?
Following the results of the allergy test, you’ll be able to pinpoint the allergens causing your symptoms and begin preparing for when and how to anticipate your triggers. You will likely find that simple adjustments to your daily or night-time routine can prevent or limit the allergens from causing you discomfort and enjoy life to your fullest.
REFERENCES
- Allergy Overview: Diagnosis and Tests. Cleveland Clinic. Accessed March 19, 2020.
- Skin Test. American College of Allergy, Asthma & Immunology. Accessed March 19, 2020.
- Do You Have Allergies? How Testing Works. Cleveland Clinic. Accessed June 25, 2020.
- Principles of Allergy Diagnosis. Accessed March 4 2022
- Allergy Testing. Cleveland Clinic. Accessed November 10, 2021
- Allergy Foundation of America. Accessed November 30, 2021
- Allergy Testing: Types, Risks and Next Steps. Accessed March 4 2022
