A skin rash from a skin allergy is called allergic contact dermatitis. Skin allergies can be acute, as in the case of poison ivy or poison oak, or chronic, from exposure to an allergic substance over a period of time. In addition, many skin conditions such as eczema, atopic dermatitis, and stasis dermatitis can also be exacerbated by an allergic reaction. In many cases of skin allergy, patients will present with a chronic rash that is resistant to or only partially controlled with treatment. A detailed history combined with patch testing is helpful in evaluating these patients and determining whether they may have allergic contact dermatitis.
Our dermatologists perform skin allergy testing using patch tests that contain many common allergic substances. The patches containing the skin allergen are applied to the skin, removed after two days, and the area is then evaluated for an allergic skin reaction. If the area becomes red, raised, or itchy this may signify an allergic reaction to the substance tested.