Dermatitis is a skin problem. The skin becomes red, swollen, and sore, and it often itches. It is not one single illness with one cause. Soap, a metal watch strap, heat, or an allergy can all start it. Doctors use dermatitis as the medical name; at home, many families say a rash, or eczema for one common kind. You do not need the long word with a friend — my skin is itchy is enough — but you will see it on cream boxes and hospital paper. Though actually, it does not mean the skin is dirty, and you did not catch it like a cold. The skin is reacting.