A Comprehensive Guide to Skin Prick Allergy Test

by Yuyu. Published on .

Are you tired of dealing with mysterious skin rashes, persistent sneezing, or unexplained itching?

Having allergic reactions can be a substantial hurdle in life, making it not only discomforting but sometimes even dangerous. Therefore, it becomes crucial to identify the triggers behind them.

In this article, we will delve into the intricacies of this diagnostic tool, exploring its procedure, benefits, and what to expect during and after the test.

Skin Prick Allergy Test

Understanding What is Allergies?

Allergies, the body's exaggerated response to seemingly harmless substances, can manifest in various forms, from mild irritations to severe and life-threatening reactions.

Identifying and understanding the types of allergies is crucial for effective management.

Common culprits include airborne allergens like pollen, mold, and dust mites, as well as food items such as nuts, dairy, and shellfish.

These allergies can significantly impact daily life, affecting everything from respiratory health to overall well-being.

As we explore the skin prick allergy test, it's essential to grasp the significance of allergy identification in alleviating symptoms and improving the quality of life for individuals affected by these immune responses.

What is a Skin Prick Allergy Test?

The skin prick allergy test, one of the widely used diagnostic tools, is designed to pinpoint specific allergens triggering adverse reactions in individuals.

This non-invasive procedure works by introducing a small amount of potential allergens to the skin surface through tiny pricks to observe the immune system's response.

The body's reaction, visible as a small raised bump, helps allergists identify the substances causing discomfort. This test is recommended when allergic reactions are suspected, and its efficiency lies in its ability to cover a broad spectrum of allergens.

Overall, a skin prick allergy test is a fast, convenient, and minimally invasive way to screen for allergies using a panel of common environmental or food allergens.

The results provide valuable information about which substances may be triggering an allergic reaction in an individual.

Why Do You Need a Skin Prick Test?

A skin prick allergy test is recommended if you have symptoms of allergies, such as:

  • Runny nose

  • Sneezing

  • Itchy, watery eyes

  • Wheezing

  • Coughing

  • Shortness of breath

  • Itchy skin rash

  • Swelling of the lips, face, tongue, or throat

Allergy testing helps determine exactly what you are allergic to. This is important for accurate diagnosis and effective treatment. Skin testing identifies allergen-specific IgE antibodies that react with the allergens.

How to Prepare for a Skin Prick Allergy Test?

Before undergoing a skin prick allergy test, proper preparation is key to obtaining reliable results.

First, make sure you consult with an allergist to discuss your medical history and symptoms.

Certain medications, such as antihistamines, may interfere with the test, so adhering to pre-test instructions is vital.

Patients are typically advised to refrain from taking these medications for a week or as advised before the test to ensure accurate and conclusive results.

Here are some other tips you could follow to prepare yourself:

  • Do not use steroid creams or ointments on the arms or back for 1 week before the test as this may suppress a reaction.

  • Wear a short-sleeved shirt so arms are accessible for testing.

  • Do not apply lotion, perfumes, or scented products on the day of the test as this can interfere.

  • Shower and wash your arms and back the morning of the test to remove any residue.

  • Do not exercise right before the test as this may make skin reactions less pronounced.

  • Eat as you normally would and take other regular medications.

  • Arrive with clean skin, no clothing that covers the arms and back, and be off antihistamines for the recommended window.

Let your doctor know if you have any questions about properly preparing for the test and discontinuing medications.

What to Expect During the Test?

The actual procedure of the skin prick allergy test is simple and straightforward.

The allergist uses a small device to introduce tiny amounts of allergens under the skin's surface, usually on the forearm or back.

Contrary to common misconceptions, the pricks are generally well-tolerated, causing minimal discomfort.

The test's duration is relatively short, with results appearing within 15 to 20 minutes.

During this time, the allergist observes the skin's reaction, noting the size of wheals and flares to determine the presence and severity of allergies.

Here's a step-by-step overview of what you can expect:

  • The allergist or nurse will first clean and mark sections on your arm or back where the allergen extracts will be applied. This is done to keep track of what extracts cause a reaction.

  • Very small amounts of standardized allergen extracts will be placed on the marked skin sections. Allergens tested can include pollens, molds, pet dander, dust mites, foods, insect venoms, latex, medications, etc.

  • A disposable plastic applicator with a 1mm tip is used to prick or slightly scratch the skin underneath each allergen droplet to introduce it into the skin's surface. The prick depth is only about 1/100th of an inch and is not deep enough to draw blood.

  • After pricking the extracts into the skin, the allergens are left on the arm/back for around 10-15 minutes. This gives time for a reaction to develop.

  • During this waiting period, the allergist or nurse will outline the area around each allergen with a marker and check back after the timed interval to examine for any raised welts or flare reaction.

  • The size of each wheal or welt is measured with a ruler to quantify the degree of reaction. Results are recorded on a chart to document your reactions.

  • After examining and measuring responses, the allergist will clean off the arm or back. Some minor itching at the test sites can occur but typically resolves quickly.

  • The pinpricks themselves require no aftercare and you can resume normal activities right away with no downtime needed.

What are Common Allergens Tested?

A skin prick allergy test covers a broad spectrum of common allergens as well as various foods. Understanding the specific allergens being tested is crucial for patients seeking clarity on their triggers.

The test helps identify not only the presence of allergies but also the degree of sensitivity, allowing for tailored treatment plans.

Here are some of the most frequently tested allergens:

  • Pollens - Grass, tree, and weed pollens are common triggers for seasonal allergies. Specific pollens tested can vary by geographic region.

  • Dust mites - Microscopic dust mites in bedding, upholstered furniture, and carpets are a pervasive household allergen.

  • Pet dander - Skin flakes and saliva from cats, dogs, and other furred pets can cause allergic reactions.

  • Molds - Both outdoor molds on decaying vegetation and indoor molds in damp areas can trigger allergy symptoms for sensitive individuals.

  • Foods - Common food allergens like peanuts, tree nuts, milk, eggs, soy, wheat, fish, and shellfish may be tested.

  • Insect stings - Allergic reactions to stinging insects like bees, wasps, hornets, and fire ants can be identified.

  • Medications - Antibiotics like penicillin and other drugs may cause allergic reactions in some people.

  • Latex - Latex gloves, balloons, and other products contain latex proteins that can trigger allergic reactions.

The allergist will choose a customized set of allergens to test based on your symptoms and medical history. This helps identify your unique allergy triggers so they can be avoided or treated accordingly.

Interpreting the Test Results

After the skin prick test is completed, the doctor will assess and measure the size of each wheal (swelling) and flare (surrounding redness) reaction.

A positive reaction indicates sensitivity to a particular allergen, while a negative result suggests no significant sensitivity.

The size of the raised areas correlates with the severity of the allergy. The results are then compared to the negative control.

  • A wheal 3mm larger than the negative control is considered positive. This means you are likely allergic to that substance.

  • A wheal the same size or slightly larger than the negative control is considered negative. You are unlikely to be allergic.

  • Very large wheals over 10mm indicate a high level of sensitivity. Smaller wheals between 3-5mm indicate a lower sensitivity.

False positives and negatives are possible due to the following scenarios:

  • False positives can occur if you have sensitive skin that reacts to any prick. Antihistamines and certain medications can also suppress true reactions.

  • False negatives may happen if you have a very mild allergy or low levels of IgE antibodies. The skin test may miss these.

Skin testing has an accuracy rate of about 85%.

Armed with this information, allergists can craft personalized treatment plans, incorporating avoidance strategies, medications, and lifestyle adjustments tailored to the individual's specific allergic profile.

What Treatment Options Are Available?

Once the allergens that trigger a reaction have been identified through skin prick testing, your doctor can work with you to develop a treatment plan to help manage your allergy symptoms.

Some of the most common treatment options include:

  • Allergy Medications - Antihistamines like Zyrtec, Claritin, or Allegra can help block histamine and reduce allergy symptoms like sneezing, itchy eyes, and runny nose. Nasal sprays like Flonase and Nasacort can help reduce nasal congestion and inflammation. Your doctor may recommend trying different medications or combinations to find the most effective regimen for your specific allergies.

  • Allergen Immunotherapy or Allergy Shots - Allergy shots or immunotherapy is a long-term treatment technique that involves receiving regular injections of small amounts of the allergens you are sensitive to. Over time, these shots can help your body build up a tolerance and reduce your immune system's overreaction to those allergens. Allergy shots are often effective for environmental allergies like pollen and dust mites.

  • Avoidance - Reducing exposure to the substances you are allergic to is an important part of managing symptoms. This may involve making environmental changes like using air filters and keeping pets out of the bedroom if you are allergic. It also means avoiding foods that trigger reactions. Your doctor can provide specific avoidance recommendations based on your test results.

  • Additional Medications - For severe food allergies, your doctor may prescribe an epinephrine auto-injector like EpiPen in case of anaphylaxis. Anti-nausea or anti-diarrheal medications can help manage digestive issues related to food allergies. Steroid creams and other topical treatments can relieve skin reactions.

  • Sublingual Immunotherapy - An alternative treatment method for allergies without injections that involves placing liquid extracts of allergens under the tongue to gradually desensitize the immune system. It is a highly effective and safer form of allergy treatment that works by targeting a specific allergen and modifying your immune system to adapt and de-sensitize against the identified allergen. This can be used for environmental and food allergies.

  • Alternative Therapies - Some patients find relief using alternative treatments like acupuncture, herbal supplements, or allergy-reducing diets, but discuss these options with your doctor first. They likely work best alongside traditional treatments.

With an appropriate, personalized treatment plan, most people can effectively manage their allergy symptoms and reduce reactions to triggers. Ongoing follow-up is important to track progress and adjust treatments as needed.

Advantages and Limitations of Skin Prick Allergy Testing

While the Skin Prick Allergy Test offers numerous advantages, including quick results and broad coverage of allergens, it's essential to acknowledge its limitations.

Factors such as medication use, skin conditions, and the inability to test for certain allergens may impact the test's accuracy.

Exploring the pros and cons provides a balanced perspective, allowing individuals to make informed decisions about their allergy testing journey.

What are the differences between Skin Prick and Blood Tests?

The skin prick test and the blood test are the two main types of allergy tests. While both check for antibodies to potential allergens, there are some key differences:

  • The skin prick test involves pricking the skin with small amounts of allergen extracts. A positive result is seen as a raised, itchy bump on the skin. Blood tests measure antibodies in the blood, with higher levels indicating an allergy.

  • Skin prick tests are more sensitive and can detect allergies earlier than blood tests. However, blood tests may detect some allergies that skin tests miss.

  • Skin prick testing shows immediate allergic reactions that develop within minutes. Blood tests detect antibodies that take weeks to develop after exposure.

  • Skin prick tests can test for multiple allergens at once and results are seen within 15-20 minutes. Blood tests usually test for 1-2 allergens and results can take 1-2 weeks before your results is ready after lab processing.

  • Skin tests carry a very small risk of a systemic reaction. Blood tests have no risk of allergic reaction.

  • Skin prick testing requires stopping antihistamines for 3-10 days beforehand. No medication adjustment is needed for blood tests.

  • Skin tests are less expensive, safer, and provide quicker results than blood tests. However, blood tests may be preferred if the patient has widespread skin disease, is at high risk of anaphylaxis, or cannot stop taking medications that interfere with skin testing.

Overall, skin testing is more accurate than blood tests at detecting true allergies. Blood tests measure antibodies in the blood, but skin testing looks directly for a reaction on the skin's surface from exposure to allergens. Skin prick testing is the gold standard for allergy testing.

Is Skin Prick Allergy Test Safe for Baby and Children?

The skin prick allergy test is generally considered safe for children and babies, but there are important considerations and guidelines to follow.

Here are key points to keep in mind:

Age Considerations: Skin prick tests are often performed on children as young as a few months old. However, the decision to conduct the test may depend on the child's ability to tolerate the procedure. Infants and very young children may not understand the need to remain still during the test, which could affect the accuracy of the results.

Allergist's Expertise: It's crucial to have the test administered by a qualified allergist with experience in pediatric allergy testing. Pediatric allergists are skilled in adapting testing procedures to the specific needs and sensitivities of children.

Parental Consent: Before conducting a skin prick allergy test on a child, parental consent is typically required. The allergist will explain the procedure, potential risks, and benefits to ensure that parents are well-informed before making a decision.

Test Site Selection: The test is usually performed on the child's back or forearm. The chosen site should be free from skin conditions, scratches, or irritation to ensure accurate results.

Potential Discomfort: While the procedure is generally well-tolerated, children may experience mild discomfort or itching at the test site. This is typically temporary and resolves on its own.

Medication Adjustments: Just like with adults, certain medications can interfere with the test results. The allergist may advise temporarily discontinuing antihistamines or other medications before the test. Always follow the allergist's guidance regarding medication adjustments for your child.

Monitoring for Reactions: After the test, it's essential to monitor the child for any delayed reactions. The allergist will provide post-test care instructions, and parents should follow these recommendations to ensure the child's well-being.

It's important to note that while skin prick testing is a valuable tool for identifying allergens, it may not be suitable for every child. In some cases, alternative testing methods or a combination of diagnostic approaches may be recommended based on the child's age, health status, and specific circumstances.

Before scheduling a skin prick allergy test for a child, it is advisable to consult with a pediatric allergist who can assess the individual situation and provide personalized recommendations for allergy testing and management. Always prioritize open communication with the healthcare provider to address any concerns and ensure the safety and well-being of the child.

How Much Does It Cost? Is It Covered by Insurance?

The cost of skin prick allergy testing can vary based on your location, the provider performing the test, and how many allergens you get tested for. On average, skin prick tests cost between $200-$500 without insurance.

Many health insurance plans cover allergy testing, but the amount of coverage depends on your specific plan. Most cover skin prick testing either fully or with a small copay, though you may need a referral from your primary care provider first. The allergist's office can check your insurance benefits beforehand to give you an idea of how much you'll need to pay out of pocket.

If skin prick testing is not covered by your insurance, or you do not have insurance, ask your allergist's office if they offer any discounts for self-pay patients. Some practices charge on a sliding scale based on income. You can also ask about paying the bill in installments if needed.

With the high prevalence of allergies, most insurance companies recognize the importance of allergy testing for accurate diagnosis and treatment. Checking your specific benefits and discussing costs upfront with your allergist can help you get the testing you need without breaking the bank.

Useful Tips to Manage Your Allergies

Apart from medications and immunotherapy, there are a few lifestyle changes you could make to help manage your allergies, such as:

  • Keep windows in your home and car closed, especially during allergy season. Use air conditioning if possible.

  • Limit your time outdoors when pollen counts are high.

  • Shower after spending time outdoors to remove pollen from your hair and skin.

  • Wear a mask when doing yardwork or housework to limit exposure to dust and allergens.

  • Use a dehumidifier and air purifier with HEPA filters in your home.

  • Wash bedding weekly in hot water to reduce dust mites.

  • Consider getting allergy covers for pillows, mattresses, and box springs.

  • Clean often to remove pet dander, dust, and other allergens. Use a microfiber cloth and avoid feather dusters.

  • Monitor pollen and air quality forecasts daily.

Making lifestyle changes can help you successfully manage both seasonal and year-round allergies.


In conclusion, the skin prick allergy test is a valuable diagnostic tool that aids in identifying the specific allergens wreaking havoc on your immune system. A better understanding of this test, as presented in our comprehensive guide, can pave the way for improved management of allergies, ushering in a more comfortable and symptom-free life for those afflicted.

Although dealing with allergies can be challenging, armed with the right knowledge, proactive measures, and treatment protocols, it's entirely possible to navigate life with ease and comfort.

Don't let allergies get the better of you; take charge of your health today.

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