Pityriasis alba is a common skin disorder similar to very mild eczema.
The cause is unknown. The disorder is most common in children and adolescents -- particularly in children with dark skin.
Round or oval, colorless patches of skin appear on the face, upper arms, neck, and upper middle of the body. There may be flaky skin, called scales.
The patches don't tan, but may get red quickly in the sun.
Symptoms are treated with moisturizers and mild topical steroid creams. The patches usually clear up, but may return.