Pityriasis Rosea

**Semantic type:** Disease or Syndrome

**Definition:** A mild, self-limited skin disorder that is most commonly seen in children and young adults. It is characterized by an initial large round spot on the chest, abdomen, or back, often referred to as a herald patch, that is usually followed within a week by a distinctive pattern of similar but smaller papules on the torso, arms, and legs. There may also be itching, especially when overheated.