A rash is a noticeable change in the texture or color of your skin. Your skin may become scaly, bumpy, itchy, or otherwise irritated. Also, skin rashes can occur from a variety of factors, including infections, heat, allergens, immune system disorders and medications. One of the most common skin disorders that causes a rash is atopic dermatitis (ay-TOP-ik dur-muh-TI-tis), also known as eczema.
Atopic dermatitis is an ongoing (chronic) condition that makes skin red and itchy. Most often it appears as patches on the hands, feet, ankles, neck, upper body and limbs. It tends to flare up periodically and then subside for a time.