Contact allergy is a delayed reaction that can causes rashes. Reactions can range in severity from mild redness to blistering of the skin. There are two types of contact dermatitis: irritant and allergic. Irritant reactions are caused by substances that irritate and cause direct damage to the skin while allergic reactions are caused by substances that trigger an immune response. Common topical substances that people are allergic to include nickel and cobalt, neomycin (a topical antibiotic), fragrance and other preservatives that are found in cosmetic products and lotions. Unlike eczema, one does not need to have an allergic predisposition to have contact allergy. In addition, contact allergy may takes years to develop; one can develop an allergy to a lotion that they have been using for years.Patch testing is available and is very helpful in the identification of substances that cause contact allergy. Testing involves placing patches on the back with various chemicals that contact the skin directly for 2 days. Patches are removed and read on days 3 and 5 to evaluate for reaction. At Flatiron Allergy, we offer the North American 80 Panel which is a very comprehensive panel covering 80 different substances that commonly cause contact allergy. If you think you may have a contact allergy, please call us and schedule an appointment.