Contact dermatitis can be due to contact with either allergens or irritants. Both types of contact dermatitis can cause the skin to become red and itchy. Many chemical substances can cause these skin reactions such as costume jewelry or fragrances in cosmetic products. The allergens responsible for allergic contact dermatitis (ACD) can be tested for using specialized allergens and the procedure is called patch testing. Patch testing requires three visits in one week. On the 1st visit allergens are placed on the back using specialized chambers which are affixed to the skin with tape. On the 2nd visit, the allergens are removed and the test sites are evaluated. On the 3rd and final visit, the test sites are re-evaluated and the patient is educated about the results.
Patch testing can be performed using a limited series of allergens or using a more extensive customized series of allergens. Dr. Ehrlich performs patch testing with multiple allergen series and tries to personalize the testing experience for each patient. She regularly tests patients who have experienced recurrent rashes and have difficulty with wearing cosmetics or problems with medical devices. She has been director of a referral patch testing clinic in the metro DC area for the past 17 years and has published and lectured extensively on contact dermatitis. Her publications on contact dermatitis include recommendations on specialized trays for vaginal, stoma, and shoe dermatitis. She is an active member of the American Contact Dermatitis Society and continually adapts her testing materials as allergens evolves.