What is patch testing?
Patch testing is a type of skin allergy test that is done when your child’s dermatologist is trying to identify what might be causing the skin to react with bumps or itchy rashes as a result from direct contact with an allergen.
Patch testing is different from other allergy testing — which can be done in just one office visit — because your child will have allergen patches in contact with their skin for two days. The allergen patches are then removed, and you child will be seen four days after the initial visit for the results to be read. Once the test is complete, your child’s dermatologist will review the results with you.
What to expect from allergy patch testing
If your child has a skin allergy patch test scheduled, you can expect:
- Your child’s dermatologist will place a number of patches containing potential allergens on your child’s back and/or thighs.
- For the duration of the test, your child should keep the patches dry. Avoid showers/baths, swimming, water parks, sprinklers, etc. Even strenuous exercise during testing can interfere with test results due to perspiration (sweating).
- The patches will stay on your child’s skin for two days. It is important to note that your child’s skin might be itchy or feel tight, but the patches should never be painful.
- After two days, the patches will be removed but your child will still have to keep their back dry until the patches are read by their dermatologist. Avoid scratching as much as possible until the patches are read.
- Four to seven days later, you and your child will go back to the dermatologist to see if any of the allergens might be causing your child’s skin to react with bumps or itchy rashes.
Patch testing helps identify what substances may be causing your child’s skin to break out in an allergic reaction. Based on your child’s results, your dermatologist will create a detailed treatment plan to help you avoid the allergens that caused the reactions. If you or your child have any concerns while the patch testing is underway, please contact the Dermatology Program at 617-355-6117.
Common skin allergies patch testing identifies
Common skin allergens that patch testing can help identify may include:
- Fragrances
- Metals
- Topical antibiotics
- Preservatives
- Surfactants (found in shampoo, body wash, hand soap, etc.)
After patch testing, your child’s dermatologist will help guide you on what ingredients in personal care products to avoid and provide you with a “safe list” of products that do not contain any of the allergens to which your child tested positive.
Patch Testing | Programs & Services
Programs
Allergy and Asthma Program
Program
The Allergy and Asthma Program evaluates children with all types of allergic problems.
Atopic Dermatitis Center
Program
The Atopic Dermatitis Center helps children and adolescents cope with severe atopic dermatitis (eczema).
Dermatology Program
Program
The Dermatology Program provides care for children and adolescents with congenital and acquired disorders of the skin, nails, hair, and mucous membranes.
