Allergy Skin Testing

Allergy tests, combined with the knowledge of your allergy specialist to interpret them, can give precise information as to what you are or are not allergic to. Testing done by an allergist is safe and effective for adults and children of all ages, including infants.

Types of Allergy Testing:

Allergy Skin Testing: 

The most common and accurate test for allergies is a skin test, also known as a skin prick (percutaneous) test. Skin testing is fast, relatively painless, more reliable and usually less expensive than blood testing.  Skin test results are available in 20 minutes and it is safe for all ages, from infants to the elderly.

This simple in-office procedure introduces a small amount of a specific allergen through an indentation or “prick” on the surface of the skin. The pricks are done with a device resembling plastic toothpicks and are typically performed on the back or forearm. After 20 minutes, the testing is interpreted by our trained staff. If you are allergic to an allergen, you will have itching, redness, and a small mosquito bite-like bump where the allergen was placed. Following the skin prick test, some patients may also receive intradermal skin testing in which a small amount of allergen is injected within the skin of the arm to see if it causes a reaction.

Allergy skin tests are safe and minimally invasive. Results of skin testing have proven to be more accurate than blood testing in detecting allergic conditions. Our Board-Certified physicians are proficient in allergy skin testing. They will take the time to discuss your personalized allergy skin test profile with you and form a highly effective treatment plan with you before you leave your appointment that day.

Prior to performing skin prick testing, it is crucial to stop all medications that may interfere with our testing for at least 7 days before the procedure. A full list of medications to be avoided can be found here. Do not stop taking your asthma medications or other routine medications without checking with your prescribing physician.

Please read these important instructions before your allergy skin testing appointment:

• How to prepare for your allergy skin testing appointment
• Antihistamine medications should be stopped one week prior to skin testing. Please review our list of drugs to avoid/stop 7 days before skin testing.

Allergy Blood Testing: 

Although allergy skin tests are the preferred method for identifying your allergic triggers, in some instances your allergist may order a blood test in place of, or along with, a skin test to confirm your allergies. The blood testing ordered will be a RAST test (radioimmunoassay test) and its purpose is to detect specific antibodies to suspected or known allergens to help guide a diagnosis. Blood tests are sometimes used:

• If the patient is taking a mediation that could interfere with the skin test results
• If the patient has extremely sensitive skin or a serious skin condition

Results of a blood test are not immediately available, and it may take up to a week to obtain results from the laboratory.

Other Allergy Testing: 

Patch Testing: This form of testing is indicated to help find the cause of skin contact allergy or contact dermatitis. Patches, treated with different chemicals or skin sensitizers to which people are most commonly allergic, are applied to the back. At North Texas Allergy and Asthma Center, we offer patch testing with a larger standardized panel consisting of 68 common allergens (North American Contact Dermatitis Group 68 series). The skin is then examined for possible local reactions usually 24 hours after application of the patch and again at 48 or 72 hours.

Challenge Testing: Challenge testing involves introducing gradually increasing amounts of suspected allergen to determine if you are still allergic to the allergen (foods, medications, vaccines). For example, during an oral food challenge, our trained staff will administer increasing amounts of food to help determine if you are still reactive to that food. Our staff will monitor you carefully and are well trained to manage allergic reactions should they occur during the challenge.

Lung Function Testing/ Spirometry: Spirometry is a test of lung function that measures how much air volume your lungs can hold and how fast you can move air out of your lungs. It is particularly valuable for those with possible asthma and can be used to monitor asthma over time.

CT Scan of the Sinuses: Our on-site state-of-the-art Xoran MiniCAT CT scanner allows us to safely and painlessly image your sinuses and identify signs of sinusitis, nasal polyposis, and other structural abnormalities in less than 1 minute. All CT scans performed in-office are overread by a board-certified radiologist. Intersocietal Accreditation Commission (IAC) requirements ensure that an imaging facility is providing high quality care and held to industry standards. Our center is a fully IAC accredited facility and our physicians are certified to perform and review the CT results with you immediately and direct appropriate treatment. At North Texas Allergy, our board-certified allergists can help perform a comprehensive allergy evaluation and perform appropriate allergy testing. For an appointment with one of our pediatric and adult allergy specialists please contact us.