Patch Testing is useful in diagnosing the cause of a very itchy rash called allergic contact dermatitis that may be due to a skin allergy. Patch testing can also be helpful in uncovering the cause of burning skin and some types of itching.
Our office uses the allergEAZE North American Standard Series for allergy testing which tests for 70 allergens.
Patch testing is indicated for use as an aid in the diagnosis of allergic contact dermatitis for person 18 years of age and older. The allergens are loaded into patch chambers and applied to the patient’s back.
Patch testing identifies allergens that come into direct contact with the skin like those found in personal care products, fragrances, clothing, jewelry or topical medications. Patch testing is very different from skin prick testing that is done by an allergist. Patch testing will not tell you if you are allergic to certain foods, animals or pollens.
Patch testing can be extremely helpful in uncovering the cause of allergic contact dermatitis and itching, but it is not always conclusive. Patients should be aware prior to the testing that the results may not be definitive and may, in some cases, be clinically irrelevant.
Patch testing requires commitment on the part of the patient. The patient is required to schedule 3 appointments over a 5-day period. The patient will have the patch test placed on a Monday (this involves putting sticky paper on the back), return to the office on Wednesday for patch removal, and return to the office on Friday for the final reading/results.
The patient may take one gentle shower between Monday and Wednesday but must not get their back wet after patches are removed on Wednesday, as this could result in a false negative reading. During the entire patch testing week, patients are encouraged to refrain from activities that may cause excessive sweating like spinning, running or kick boxing for example. For best results, patients should not take anti-histamine pills (also known as allergy pills) or use topical or oral corticosteroids while undergoing patch testing.
Serious side effects from patch testing are rare. The most common side effect is itching at the site, which resolves upon completion of the test.