Allergy Skin Testing
Prick Skin Test
Prick skin testing and intradermal skin testing are relatively fast methods of identifying allergies. The results of these types of testing are available within 15 to 20 minutes after the tests are applied. Both prick skin testing and intradermal skin testing are commonly used to determine what you are allergic to, as well as the severity of the allergy.
Preparing For the Test
Please discuss with your doctor any medications you should discontinue prior to your allergy testing and other test preparation requirements. Antihistamines may affect the results of these tests and need to be stopped before testing is performed. Some over-the-counter cold and flu medications contain an antihistamine, so be sure to read labels carefully. If you are not sure if the medicine you are taking has an antihistamine, ask your doctor.
Continue to take all your other medicine as you usually do. Inhaled, nasal and oral glucocorticoids (steroids) will not interfere with the results of your skin testing.
Do not apply lotions or creams to your back the day of your appointment.
During The Test
When prick skin testing is done, a small amount of each thing you may be allergic to (allergen) is placed on the skin (usually your back). The skin is then pricked with a small plastic pick. If you are allergic to an allergen, you will get a bump and redness where the skin is pricked. After a short time (15 minutes), each skin test reaction is measured for swelling and redness. A positive reaction indicates that you may be allergic to that allergen. Your doctor will compare your prick skin test results with your history of symptoms.
Length Of The Test
Allergy skin testing may take up to 2 hours to complete.
Intradermal Skin Testing
When intradermal skin testing is done, a small amount of each thing you may be allergic to (allergen) is injected under the skin. Like prick skin testing, if you are allergic to an allergen, you will get a bump and redness where the allergen was injected. After a short time, each skin test reaction is measured. A positive reaction indicates that you may be allergic to that allergen. Your doctor will compare your intradermal skin test results with your history of symptoms. A combination of the prick and intradermal testing can give an idea of the relative severity of the allergy.
Allergy Patch Testing
Patch skin testing can be used to find out if a rash is from direct contact with an allergen. Generally, the nature of this type of reaction is slower to develop which is why patch testing requires 3 sequential visits for completion.
Preparing For The Test
Please discuss with your doctor any medications you should discontinue prior to your allergy testing and other test preparation requirements. Antihistamines may affect the results of these tests and need to be stopped before testing is performed. Some over-the-counter cold and flu medications contain an antihistamine, so be sure to read labels carefully. If you are not sure if the medicine you are taking has an antihistamine, ask your doctor.
During The Test
You will visit us a number of times during patch testing. The patch tests are placed during the first visit. Patch tests include two or three rectangular panels (approximately the size of a 3” x 5” card) with small amounts of pre-applied allergens. Sometimes individual patch tests may be applied. The tests are placed on the skin, typically the back. The panels also have acrylic tape as part of the panel. This will help the panels adhere to the skin for two days. After two days the panels are removed and the skin reactions are measured. You will come back again one or two days after the panels are removed to measure the skin reactions again. We will provide you with information regarding the results at the final visit.
Venom Skin Testing
Skin testing for venom allergy (bees, wasps, hornets and fire ants) involves both prick skin testing and intradermal testing. There are a series of skin tests performed with venom testing so the duration of testing will be a little longer than with other types of allergy skin tests.
Preparing For The Test
Please discuss with your doctor any medications you should discontinue prior to your allergy testing and other test preparation requirements. Antihistamines may affect the results of these tests and need to be stopped before testing is performed. Some over-the-counter cold and flu medications contain an antihistamine, so be sure to read labels carefully. If you are not sure if the medicine you are taking has an antihistamine, ask your doctor.
During The Test
Testing for venom allergy after a “bee sting” involves both prick and intradermal skin tests. If indicated, fire ant allergy can also be tested in this manner. Testing to the following venoms is performed in all patients reporting a possible bee sting allergy: honeybee, white-faced hornet, yellow-faced hornet, yellow jacket and wasp. First, prick skin testing is performed to each of the venoms then, intradermal testing is performed. If there is a positive reaction to any venom, then testing for that venom stops. A positive reaction indicates that you may be allergic to that venom. Your doctor will compare your skin test results with your history of symptoms. We may also order blood testing to further investigate for venom allergy.
Length Of The Test
Venom allergy skin testing usually takes 90 minutes to complete.
Penicillin Skin Testing
Skin testing for penicillin allergy involves both prick skin testing and intradermal testing. There are a series of skin tests performed with penicillin testing so the duration of testing will be a little longer than with other types of allergy skin tests.
Preparing For The Test
Please discuss with your doctor any medications you should discontinue prior to your allergy testing and other test preparation requirements. Antihistamines may affect the results of these tests and need to be stopped before testing is performed. Some over-the-counter cold and flu medications contain an antihistamine, so be sure to read labels carefully. If you are not sure if the medicine you are taking has an antihistamine, ask your doctor.
During The Test
Testing for penicillin allergy starts with prick skin testing to penicillin and a related medication called PrePen. After prick skin testing, intradermal testing is then performed with each of the substances. If there is a positive reaction to any of the tests, testing stops. A positive reaction indicates that you are most likely allergic to penicillin. If all skin testing is negative, in the final step of your evaluation you will be given amoxicillin in the clinic and observed closely for any reaction.
Length Of The Test
Penicillin allergy testing usually takes about 90 minutes to complete.
Frequently Asked Questions about Allergy Skin Testing
Does allergy skin testing hurt?
Allergy skin testing causes only mild, brief discomfort rather than real pain. Prick testing feels like a light scratch on the surface of the skin, and intradermal testing involves a small injection just under the skin that stings for a moment. If you’re allergic, you may get an itchy bump and redness at that spot, which usually settles within an hour or two. The allergy team at ENT Specialists of Wisconsin stays with you throughout to measure reactions and keep you comfortable.
How accurate is allergy skin testing?
Allergy skin testing is considered highly reliable and is one of the most accurate ways to identify environmental and stinging-insect allergies. A positive reaction shows sensitivity, but results are always read alongside your symptom history, because a bump alone doesn’t confirm a clinically meaningful allergy. Combining prick and intradermal testing improves accuracy and helps gauge how strong a reaction is. Occasionally a repeat test or blood work is added when results and symptoms don’t line up.
Skin testing vs. a blood test for allergies: which is better?
Skin testing is usually the first choice because it’s fast, sensitive, and gives results in about 15 to 20 minutes, while a blood test is better in specific situations. Blood testing is helpful when you can’t stop antihistamines, have a skin condition covering the test area, or have a history of severe reactions. Neither is universally “better,” and your provider chooses based on your history and safety. Sometimes both are used together for a clearer picture.
How long before allergy testing do I need to stop antihistamines?
Most people need to stop antihistamines about five to seven days before allergy skin testing, since these medicines blunt the reaction and can cause false-negative results. This includes many over-the-counter cold, flu, and sleep products that contain a hidden antihistamine, so read labels carefully. Keep taking your other medications as usual, including inhaled, nasal, and oral steroids, which do not interfere. Always confirm the exact stop time with your provider before your appointment.
Can I get allergy skin testing while pregnant?
Allergy skin testing is usually postponed during pregnancy as a precaution, even though the test itself is low risk. The concern is the rare chance of a strong whole-body reaction, so most providers prefer to wait until after delivery for elective testing. If understanding your allergies is urgent, a blood test is often used instead because it carries no reaction risk. Discuss timing with your provider and your obstetrician to decide what’s right for you.
Can children get allergy skin testing, and at what age?
Children can have allergy skin testing, and it’s commonly done in young kids, including toddlers, when symptoms or a strong family history warrant it. There’s no strict minimum age, since the test is quick and low risk, though very young children may be tested for fewer allergens at a time. Early testing helps manage conditions like eczema, asthma, and food reactions before they worsen. Your provider decides the right timing based on your child’s symptoms.
What happens after I get my allergy skin test results?
After your results, your provider builds a treatment plan matched to the specific allergens you reacted to. The first step is usually environmental control, meaning practical ways to reduce contact with triggers like dust mites, pet dander, or pollen. Next may come medications such as antihistamines or nasal sprays, and for ongoing or severe allergies, allergen immunotherapy to build long-term tolerance. To review your results and next steps, call ENT Specialists of Wisconsin at (920) 969-1768
Do I need to stay at the clinic after penicillin testing, and why?
Yes, you’ll be observed at the clinic after penicillin testing, especially during the final step when you take a dose of amoxicillin. This monitoring period, usually around 30 to 60 minutes, lets the team catch any delayed reaction right away in a setting equipped to treat it. Most people with negative skin tests tolerate the dose with no problem. If testing confirms a true allergy, options such as medication desensitization can be discussed when the antibiotic is truly needed.
Where can I get allergy testing near me in the Fox Valley?
You can get allergy skin testing in the Fox Valley at ENT Specialists of Wisconsin, which offers prick, intradermal, patch, venom, and penicillin testing across northeast Wisconsin. The practice has three Appleton offices on Grant Street, Meade Street, and Westhill Boulevard, plus locations in De Pere, Neenah, Oshkosh, Shawano, and Waupaca. To schedule testing, call ENT Specialists of Wisconsin at (920) 969-1768.
When is the best time of year to get allergy tested in Wisconsin?
You can get allergy tested any time of year in Wisconsin, but late winter and early spring are often ideal because they let you start treatment before pollen season peaks. Tree pollen ramps up in April and May and ragweed dominates the fall, so testing ahead of those windows gives your provider time to plan. Indoor triggers like dust mites and mold can be tested year-round. Early testing also supports building an asthma action plan before symptoms flare.