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- What allergens can a skin prick test identify?
- Who should have a skin prick test?
- Which allergies are a skin prick test recommended?
- What is the skin prick test procedure?
- How long does it take for the skin prick test result?
- What are the side effects of skin prick tests?
- What is the benefit of skin prick test?
Skin Prick Test
Skin prick test is a skin allergy test that identifies allergens by pricking the skin and dropping allergen protein extracts or food, such as nuts, cow's milk, eggs, or dust mites, one per site, to find out which allergens you are allergic to. Individuals with allergies will manifest allergic reactions, including itchiness, wheal, and red flares on the skin. Skin prick test identifies which allergens cause you an allergic reaction, such as skin allergens, food, drug allergens, or respiratory allergens, assists you in avoiding that allergen, and allows allergists to tailor precise treatment plans. Skin prick test is considered a safe preventive health screening that provides immediate test results, leading to treatment considerations, such as stimulating the body's immune system to boost strong and resistant physical health and tolerate those specific allergens.
Why skin prick test?
For those with asthma, urticaria, chronic rhinitis, anaphylaxis, angioedema, or conjunctivitis caused by some allergic-causing allergens, e.g., dust mites, pet dander, pollen, certain medications, nuts, or seafood, e.g., shrimp, crab, or fish, received by eating, breathing, or exposing and causing acute allergic reactions including coughing, sneezing, itchy rash, wheal, and red flares. Skin prick test is the most effective skin allergy test because, when the body is first exposed to an allergen, it produces IgE antibodies that bind to skin connective tissues. When the body is exposed to that particular allergen for the second or third time through a skin prick test, it will recognize and quickly manifest an allergic reaction against that particular allergen with wheal, swelling, and red flares, allowing allergists to identify an allergic-causing allergen, the true cause of allergic reactions, and leading to precise allergy treatment.
What allergens can a skin prick test identify?
Skin prick tests can detect various kinds of allergens, including the following:
- Nuts, such as soybeans, legumes, peanuts, wheat flour, or gluten-containing grains,
- Injectable or oral medications, such as penicillin.
- Pollen flowers, grasses, trees, weeds, or herbs.
- Resins, such as rubber
- House dust mites, barn mites
- Seafood, crustaceans, such as shrimp, mantis shrimp, crab, and fish.
- Eggs and egg products, milk, and dairy products
- Citrus fruits such as oranges, lemons, and grapefruits
- Fungi, such as aspergillosis or yeast
- Insect bites, insect stings
- Dandruff, or pet dander, such as dog or cat dander
Who should have a skin prick test?
Individuals with the following symptoms or underlying diseases should have a skin prick test:
- Rhinoconjunctivitis
- Allergic conjunctivitis
- Anaphylaxis
- Acute urticaria
- Rhinitis
- Asthma
- Sinusitis
- Atopic dermatitis
- Eczema
- Those with a family history of allergies
Which allergies are a skin prick test recommended?
- Nasal allergies, such as nasal congestion, runny nose, coughing, sneezing, dry coughing, rapid breathing, wheezing, and sinusitis
- Eye allergies, such as itchy eyes, eye irritation, pink eyes, swollen eyes, watery eyes, swollen eyelids, and conjunctivitis
- Respiratory allergies, such as asthma, intermittent sneezing, blocked nostrils, itchy throat, phlegm, and difficulty breathing.
- Skin allergies, such as itching, wheal, swelling, redness on skin, swelling of the eyelids and mouth, hives, flaky skin, and cracked skin.
What is the preparation for a skin prick test?
- Avoid taking antihistamines or antihistamine-containing medications for 1 week, including decongestants, anti-itching medicine, and urticaria drugs.
- Avoid sedatives, sleeping pills, dizziness medications, anti-anxiety medications, and motion sickness medications for at least 1-3 weeks.
- Abstain from taking injectable, topical, or oral steroids for at least 3 weeks. Inform the allergist if you are taking any steroid medications.
- Food and water can be consumed as usual before the test.
- The allergist will take a medical history, allergen exposure history, and allergic reaction before conducting an initial physical examination.
- Inform the allergist if you have a history of drug allergies or are taking any underlying medications or antihistamines.
What is the skin prick test procedure?
- The allergist or medical staff cleans the skin on the arm or back before performing the test.
- The medical staff uses a pen to draw a square grid on the skin, marking spaces for each allergen sample.
- The allergist applies one drop of allergen protein extract to the skin in each square grid, one type at a time.
- The allergist uses a special skin prick needle to prick the epidermis and dab the allergen protein extract.
- Then wait 15 minutes to see if there are any allergic reactions. While waiting, avoid scratching, despite you are itching, to prevent misinterpretation.
- When the waiting period is up, the allergist will look for allergic reactions on the skin, such as wheal, flare, redness, or itching, to help identify allergens.
- The allergist will disinfect the tested skin with alcohol before applying topical medication to relieve itching, swelling, or redness.
- Typically, a skin prick test takes approximately 20 minutes. Any wheal from allergic reactions will gradually subside on their own within 1-2 hours.
What does the skin prick test result mean?
Skin prick test results can be interpreted into 4 types, as follows:
Positive
A positive test result demonstrates wheal, flare, or redness on the skin. There is an allergic symptom or allergic reaction to the allergen tested on the skin.
Negative
A negative test result demonstrates no wheal, flare, or redness on the skin. There are no allergic symptoms or allergic reactions to the allergen tested on the skin.
False positive result
A false positive result demonstrates an allergic symptom or allergic reaction to the allergen during the test, but no allergic reaction occurs when exposed to that allergen in daily life.
False negative result
A false negative result demonstrates no allergic symptoms or allergic reactions to the allergen during the test, but an allergic reaction occurs when exposed to that allergen in daily life.
How long does it take for the skin prick test result?
Typically, skin prick tests take 15-20 minutes to yield results.
What are the side effects of skin prick tests?
Common side effects of skin prick tests include itching, wheal, and flare. These symptoms will persist for 15-20 minutes to 2-3 hours following the test. Most of these side effects are mild and will gradually disappear on their own. The allergist will prescribe topical antihistamines to relieve the symptoms.
Severe side effects of skin prick tests that are very rare include anaphylaxis, which involves multi-system allergic reactions. If the test is performed at a hospital, the allergist will monitor the symptoms and initiate immediate treatment right away.
What is the benefit of skin prick test?
- Fast: A skin prick test enables allergists to identify allergy-causing allergens, such as food allergies, resulting in an accurate treatment plan within the same day.
- Informative: Skin prick tests inform patients which allergens trigger their underlying diseases, such as asthma, conjunctivitis, or atopic dermatitis, and in what quantities.
- Preventive: Skin prick test alerts individuals to avoid allergens that cause allergic reactions, such as pets.
- Precise: Skin prick tests help allergists provide specific treatment for specific allergens, such as sublingual immunotherapy or an under-the-tongue allergy drop for those allergic to dust mites, or subcutaneous immunotherapy or allergy vaccines injected under the skin for those allergic to dog or cat dander.
- Cost-effective: When comparing, skin prick tests cost less than other allergy tests, making them a more affordable option.
Skin prick test at MedPark Hospital
Allergy Clinic at MedPark Hospital, Bangkok, Thailand, led by a team of specialized allergists/immunologists at the professor level with extensive experience, is ready to provide diagnosis and treatment of allergies and all types of immune-related disorders, including single-system allergies, multi-system allergies, or anaphylaxis that require a prompt life-saving encounter, incorporate a cross-functional team to provide a consistent caring approach while utilizing state-of-the-art ISO 15189 and ISO 15190 clinical laboratories, aiding in the identification of all types of allergens, assisting in the accurate and precise interpretation of test results, leading to effective and precise treatment while preventing recurrence, stimulating immune system production, and boosting strong physical health.
