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. The disease is Monarch Disease Ontology term MONDO_0006601 (pityriasis rosea). Also known as: Pityriasis circinata, Pityriasis rosea.