Patch Test for Allergies Q&A

A patch test, also known as a skin test or skin prick, is a diagnostic tool used by an allergy specialist to help diagnose a suspected allergy. A patch test may be conducted on its own, or in conjunction with other diagnostic tests, including a physical exam, discussion of medical and family history, or a blood test. A patch test can be used to diagnose a wide variety of allergies, including hay fever (known as allergic rhinitis), asthma (that is suspected to have allergic causes), dermatitis (a general term for skin irritation, also known as eczema), food allergy, a penicillin allergy, or a bee venom allergy.

In general, patch tests are safe for everyone, including children. Your allergist will only conduct a patch test if they feel it is beneficial and safe. However, some people should not undergo patch testing, specifically, those who: have or have had a severe allergic reaction to the allergen in question, take medications that may interfere with results (such as antihistamines, heart medications, or certain antidepressants), or have skin conditions that may interfere with the ability to see and read the results of a patch test.

Patch testing is performed usually in an allergist’s office. The allergist will prick the skin with a small, concentrated form of the allergen in question, and wait to see if a hive (or wheal) develops, or if another indicator of allergy is present. The prick is usually given on the inside of the forearm, on a small, clear area of the skin. If you’re being tested for multiple allergies, you may need multiple areas of skin tested; this is more common if you had an allergic reaction or allergy symptoms, but aren’t sure of the cause. After the prick is given, the allergist will monitor the area and the symptoms present.

The actual patch test itself is quick, but the duration of the whole appointment and procedure may vary, depending on if symptoms (hives) arise, and how quickly. Your allergist will be able to determine how long you need to be observed, and how long you should remain in the appointment or at the site of the test.

For some people, the hives may onset quickly after the skin prick is conducted, but for others, the reaction may be delayed and may remain in some capacity for a period of time after the test is over. It’s very important that you have a patch test done by an allergist in a medical setting, as in some cases, a severe allergic reaction could occur, and it’s important that a professional is there with the right tools to address it.

Patch tests are generally quick, and not very painful; many people describe it as feeling like a light scratch or sting, that is resolved as soon as the prick has been administered and taken away. You may feel some discomfort and itching if hives or other allergy symptoms are present on your skin after the test, but these usually fade relatively quickly, and if not, can be treated and addressed by the specialist on hand.

To prepare for the patch test, make sure you’re aware of your (or, if you’re a parent, your child’s) medical history, allergic reaction, symptom history, and perhaps even family history of allergies, as this may be relevant. Let your allergist know of any medications you are taking, or other conditions you may be dealing with. At Piniella Asthma + Allergy, we strive to ensure our patch tests are as comfortable and efficient as possible. We serve patients from Coral Gables FL, Palmetto Bay FL, Westchester FL, Brownsville FL, Kendall FL, Pinecrest FL, Richmond West FL, and Goulds FL.