Pityriasis rosea (say "pih-tih-RY-uh-sus ROH-zee-uh) is a common skin problem that causes a rash. Salmon-colored oval patches appear in batches. They appear on the belly, chest, back, arms, and legs. Patches sometimes spread to the neck but rarely to the face.
Pityriasis rosea is usually harmless. But it can cause serious problems in pregnant women.
WebMD Medical Reference from Healthwise