George Woodbury MD 2/8/2023
What is Allergy Patch Testing?
Allergy Patch Testing is a way of trying to find out the cause of an allergic skin rash, by placing ointments containing common causes of these rashes onto your skin, then checking to see if you react to them. In my Memphis Dermatology practice, at Rheumatology and Dermatology, I have been offering Allergy Patch Testing since 2004. I am also a member of the American Contact Dermatitis Society, an 1100 Dermatologist organization focused on this type of testing.
What is meant by the term “allergen?”
An allergen is a chemical that leads to an allergic reaction. A common example is nickel. Some people tolerate contact with this metal without any reaction, whereas others are highly allergic or sensitive to it.
What is required for this type of testing?
The test requires three visits. In my Memphis Dermatology practice, I schedule this testing on a Monday, Wednesday, and Friday, generally within the same week. The Monday appointment will consist of placing the patches (the patches are applied with tape, often to the back or forearm). Wednesday the patches will be removed, and readings of this testing are taken on both the Wednesday and Friday visits. There will be a charge for each visit.
Is Allergy Patch Testing painful?
Generally, it is not painful. It does not involve any needles. On occasion, though, you may have some itching in the area, if you react to one of the patches.
What are the chances this type of test will reveal the cause of my skin problem, and give me some clinically useful information?
In about 70% of patients tested we can find a relevant item that the patient is allergic to. My Memphis Dermatologist practice, at Rheumatology and Dermatology Associates, 8143 Walnut Grove Road, Cordova TN, can then give the patient a typed handout, to help in avoidance of this chemical or chemicals, hopefully thereby allowing cure of the skin rash.
Is this type of test different from the allergy tests I have heard about at the allergist's office?
Yes, it is. Allergy Patch Testing detects causes of skin allergic reactions. The items in the test have been selected specifically for eczemas, or sensitive skin rashes. Patch testing is different from "RAST testing," which involves injections of solutions into the skin, and which is designed more around respiratory allergies or sinus allergies, which more often involves molds, danders, mildews, and tree components.
What chemicals are in the patch test kit?
We test to over 70 different chemicals. The twenty most common causes of allergic contact dermatitis are included, as well as common preservatives (in cosmetics and toiletries), metals (nickel and cobalt), latex allergens (thiuram mix and mercaptobenzothiazole), dyes (paraphenylenediamine, blue and red dyes from textiles), and fragrances (cinnamon-related chemicals).
What sort of patient gets the most results from Allergy Patch Testing?
This type of testing is most useful in those patients with sensitive skin rashes that keep recurring or coming back despite treatment, including patients with stubborn Psoriasis, Atopic Dermatitis, or Eczema, and Contact Dermatitis.
The patient in the photos below underwent Allergy Patch Testing.
During this testing, our staff placed patches with suspected chemicals onto her back. Two days later, you can see the striking reaction to a metal called Cobalt, popular in costume jewelry and ceramics work. We were able to then give her information on how to avoid cobalt, moves which have greatly helped her to avoid itchy rashes.
Suppose I have some chemical at work or home that I think I might be reacting to. Can I be tested to this chemical too?
It is easy to include additional chemicals in the patch testing panel. We do require advance notice of which chemicals might be candidates, to allow time to investigate these chemicals and their safety. We also need any relevant Material Safety Data Sheets before including these items.
Can I shower during those two days that the patches are on?
Most certainly you can, but it is advisable to keep the patches dry by securing some saran over the patch test site. Another option is to sponge bathe rather than shower. The area on the back that is being testing has to stay dry during the week when the Allergy Patch Testing is being done. So it’s best to avoid vigorous exercise during the week of testing, as well as a lot of sweating, and certainly it’s best to avoid both the hot tub and sauna.
Suppose we find that I'm allergic to everything?
About 60-70% of the patients I test are allergic to at least one of the items in the kit. Only about 10% are allergic to two. It is less common of for someone to react to more than three or four, though I have certainly had patients that reacted to eight or ten of the patches.
Do I need to bring anything with me on the days of testing?
It is often helpful if you bring some of your cosmetics and toiletries from home, as we will want to try to find out the contents. It generally works best to bring these chemicals to the Wednesday or Friday visit.
Will my insurance company cover for Allergy Patch Testing?
Most insurance companies do cover for the cost of allergy patch testing though some do subject this testing to a deductible. The service code (CPT code) for this test is 95044, with 86 units (i.e. 141 patches), and the cost per patch is $13.00.
At your discretion, you may want to check with your own insurance company regarding coverage for this possible type of allergy testing - which is called an allergy patch test. If the insurance company needs us to submit documentation in advance as to why you need this type of testing, please call our office about this
If you have additional questions about patch testing, feel free to contact me at 753-0168, or write to us at 8143 Walnut Grove Rd., Memphis, TN 38018 (or Email: Info@Rheumderm.com). And thanks for your interest.
Can the office recommend any cosmetics or toiletry products if I am found to have reactions to certain chemicals?
In addition to being a Cordova Dermatologist, I am the President of Big River Silk Skincare, focused on skincare products with lower risk of allergies for people of all ages, from babies to seniors, using a minimal number of chemicals, to minimize the risk of allergic reactions. We offer HypoShea Moisturizer Cream, free of fragrances, dyes, and propylene glycol (1 oz: $12.96/2 oz: $18.95/8 oz: $39.95, as well as HypoShea Oil for use after bathing or showering (1 oz: $7.97/2 oz: $12.95).
All products are available at www.Bigriversilkskincare.com, or at our international headquarters, at 8143 Walnut Grove Road, Cordova, TN 38018, Monday-Friday, from 7:30 AM to 4:30 PM. Or you can call us at 1-901-753-0168. We do offer free shipping and handling or US orders above $40.00 ($70.00 Canadian). Otherwise, $5.00 shipping and handling for US orders/$10.00 Canadian.
If you or a friend would like to come in for a skin consultation, my Memphis Dermatology practice has been with Rheumatology and Dermatology, 8143 Walnut Grove Road, Cordova TN 38018 since 1993 (1-901-753-0168). Or you can find a Dermatologist closer to you by going to the American Academy of Dermatology website, https://www.AADA.org, then plugging your zip code into the “Find a Dermatologist” tab. Never itch in silence!