Learn more about the symptoms, causes and treatment of this large rash common among teens and young adults.
Pityriasis rosea is a rash that often begins as an oval spot on the face, chest, abdomen or back. This is called a herald patch and may be up to 4 inches (10 centimeters) across. Then you may get smaller spots that sweep out from the middle of the body in a shape that looks like drooping pine-tree branches. The rash can be itchy.
Pityriasis (pit-ih-RIE-uh-sis) rosea can happen at any age but is most common between the ages of 10 and 35. It tends to go away on its own within 10 weeks.
Treatment may help relieve the symptoms.
The rash persists for several weeks and heals without scarring. Medicated lotions may lessen itchiness and speed the disappearance of the rash. Often, though, no treatment is required. The condition is not contagious and seldom recurs.
Pityriasis rosea typically begins with a large, slightly raised, scaly patch called the herald patch.
Pityriasis rosea typically begins with an oval, slightly raised, scaly patch — called the herald patch — on the face, back, chest or abdomen. Before the herald patch appears, some people have headache, fatigue, fever or sore throat.
A few days to a few weeks after the herald patch appears, you may notice smaller bumps or scaly spots across your face, back, chest or abdomen that look like a pine-tree pattern. The rash can cause itching.
See your health care provider if you develop a rash that gets worse or hasn't cleared up in three months.
The exact cause of pityriasis rosea is unclear. It might be triggered by an infection with a virus, particularly by certain strains of the herpes virus. But it's not related to the herpes virus that causes cold sores. Pityriasis rosea isn't contagious.
Complications of pityriasis rosea aren't likely. If they do occur, they may include:
In most cases, your health care provider can identify pityriasis rosea by looking at the rash. You might need a scraping or possibly a skin biopsy, which involves taking a small piece of the rash for testing. This test can help tell a pityriasis rosea rash from other, similar rashes.
Pityriasis rosea usually goes away on its own without treatment in 4 to 10 weeks. If the rash doesn't disappear by then or the itching bothers you, talk with your health care provider about treatments. The condition clears up without scarring and usually doesn't come back.
If home remedies don't ease symptoms or shorten the duration of pityriasis rosea, your health care provider might prescribe medicine. Examples include corticosteroids and antihistamines.
Your health care provider might also suggest light therapy. In light therapy, you're exposed to natural or artificial light that may ease your symptoms. Light therapy may cause lasting spots of skin that are darker than usual (post-inflammatory hyperpigmentation), even after the rash clears.
The following self-care tips may help relieve the discomfort of pityriasis rosea:
You're likely to start by seeing your health care provider. You might then be referred to a doctor who specializes in skin disorders (dermatologist).
Here's some information to help you get ready for your appointment.
Questions to ask your health care provider about pityriasis rosea include:
Your health care provider may ask: