Overview

Pityriasis rosea is a rash that usually begins as a large circular or oval spot on your chest, abdomen or back. Called a herald patch, this spot can be up to 4 inches (10 centimeters) across.

The herald patch is typically followed by smaller spots that sweep out from the middle of your body in a shape that resembles drooping pine-tree branches.

Pityriasis (pit-ih-RIE-uh-sis) rosea can affect any age group. It most commonly occurs between the ages of 10 and 35. It usually goes away on its own within 10 weeks. Pityriasis rosea can cause itching. Treatment may help relieve the symptoms.