Chronic urticaria, otherwise known as chronic hives is a condition that is typically characterized by the recurring presence of red raised welts somewhere on the body. These welts are typically itchy, and the source of the breakout is often unidentified. If this is the case, the condition is known more specifically as chronic idiopathic urticaria.
Allergic contact dermatitis is characterized by the presence of a red rash after coming into contact with a triggering object. The rash may or may not be itchy, and other common symptoms include inflammation, the presence of clear fluid, crusting, blistering or the presence of pustules, crusting, unusual dryness or peeling.