Allergic Contact Dermatitis and Skin Allergy Patch Testing
Allergic contact dermatitis is responsible for approximately half of all contact dermatitis cases. When patients with this condition are exposed to certain substances or materials, their immune systems respond in such a way that results in a red, itchy, and uncomfortable rash. Patients with persistent, unresolved contact dermatitis can suffer for years with a diminished quality of life as a result of their skin inflammation, and get saddled with ongoing medical treatment costs. However, the condition can be effectively treated for good once an accurate diagnosis is obtained, and the irritant is identified.
Patch testing is the gold standard for evaluating allergic contact dermatitis, and what we offer here for our patients at California Dermatology Care. Dr. William Ting is a recognized local thought leader in skin allergy patch testing, as well as a member of the American Contact Dermatitis Society. He utilizes the North American Contact Dermatitis Group’s (NACDG) comprehensive Extended Patch Test Series, which can test for 80 of the most common allergens, including nickel, parabens, and fragrance mix. Additional allergens (such as suspected skin care products) may also be tested upon request.
Patch testing is a simple procedure to help diagnose allergic contact dermatitis and identify the causative agent(s) behind the skin inflammation. The ultimate goal is to assist patients suffering from dermatitis to become better informed consumers, and be cognizant of potential allergic contact triggers of their rash. This procedure involves no pain, and consists of thin panels of a wide variety of different allergens including metals, rubber ingredients, and other chemicals that one may commonly encounter in their everyday environment, including household or certain industrial items. After the patch is applied, patients can go about their daily activities, but will need to return twice – once after 2 days to remove the patch test panels, and another follow-up visit a day or two afterwards to catch any potential delayed reactions.
Patch testing is different from skin prick allergy tests performed by allergists. Skin prick allergy testing is helpful for conditions such as allergic rhinitis or asthma as they will help elucidate type I immediate-type hypersensitivity. However, skin prick allergy tests are rarely helpful for skin sensitivities, as type IV delayed-type hypersensitivity is typically involved. Patch testing is designed specifically to isolate potential delayed-type hypersensitivity from contact triggers, which is most relevant for allergic contact dermatitis.
Food allergies are typically not a cause behind skin rashes, and thus food allergy testing is often not necessary for skin eruptions, particularly for adults 18 years and older. However, for special circumstances and upon request, Dr. Ting may order bloodwork for food allergen panels via Quest Diagnostic Laboratories.