Overview
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.
Symptoms
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.
When to see a doctor
See your health care provider if you develop a rash that gets worse or hasn't cleared up in three months.
Causes
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.
Risk factors
Having family members with pityriasis rosea increases your risk of developing the condition. Taking certain medicines may increase the risk of this condition as well. Examples include terbinafine, isotretinoin, omeprazole, gold, arsenic and barbiturates.
Complications
Complications of pityriasis rosea aren't likely. If they do occur, they may include:
- Severe itching
- Temporary spots (lasting weeks to months) of skin that are darker or lighter than usual (post-inflammatory hyperpigmentation or hypopigmentation), which is more likely in people with brown or Black skin