Allergy Testing

Contact Allergy Testing

Many people develop rashes due to sensitivities to substances present in everyday life. For example a common skin allergy is the metal Nickel and you may know somebody that develops a very severe and itchy rash if they wear costume jewelry. Another common example of a contact allergy is to the chemical on the leaves of the Poison Ivy or other toxicodendron plants. What you may not be aware of is that it is possible to develop a similar sensitivity to almost any chemical after repeated exposures, including chemicals present in everyday products such as soaps, shampoos, cleaning products, lawn care, etc. When this occurs patients develop chronic rashes that can become quite problematic. Contact allergy testing or Patch testing is a method used to isolate and identify specific chemicals people have become allergic to in order to eliminate exposures and cure the rash.

Some physician offices offer limited patch testing to a small subset of chemicals called the T.R.U.E test. Here at WassermanUlitsky Dermatology we are able to test to the full American Contact Dermatitis Society series of core allergens, which includes 80 different chemicals. More specialized allergen panels are also available on an as needed basis.

Patch testing is a multiday process composes of three separate appointments spread out over a 5 day period.

Day 1

The patient is interviewed and an exam is completed to gather information on possible causes of their contact dermatitis. Patients may bring in their products from home so the ingredients can be examined and if the patient has a specific product that they are suspicious of or wish to be tested to a patch can be designed using the chemical they bring in. At the conclusion of the visit the test panels are applied to the patients skin, usually on the back. Each panel is made up of an adhesive background with 10 individual chambers containing pure chemicals suspended in petrolatum or aqueous solutions. From this point on the test area cannot be washed until the conclusion of the test.

Day 3

The patient returns and the panels are removed. The test area is marked with a removable ink and an initial reading is done. People with particularly strong sensitivities may show a reaction on day 3, however it is not uncommon for the test to be negative at this point.

Day 5

A final reading of the test area is done and positive allergens are identified. Once the chemicals are identified the doctor will discuss where these chemicals can be found and the patient is supplied with resources to help them avoid future exposures.

If you wish to be scheduled for testing please contact the office. Once you have been scheduled, please download the following form at least 7 days prior to your test date, which will prepare you for testing.

Patch Testing Instructions