What is Patch Testing (Skin Allergies)?
Patch testing is a way of identifying whether a substance that comes in contact with the skin is causing inflammation of the skin (contact dermatitis). There are two types of contact dermatitis: irritant contact dermatitis and allergic contact dermatitis. Irritant contact dermatitis An irritant substance is one that would cause inflammation in almost every individual if it was applied in sufficiently high concentration for long enough. An irritant reaction is caused by the direct contact of an irritant substance with the skin and does not involve the immune system. Allergic contact dermatitis An allergic reaction is specific to the individual and to a substance (or a group of related substances) called an allergen. Allergy is a hypersensitivity (oversensitivity) to a particular substance, and always involves the immune system. All areas of skin that are in contact with the allergen develop the rash. The rash will disappear if you avoid contact with the substance. Patch testing can help
