Understanding Pityriasis Rosea

Front view of man's head and chest showing pityriasis rosea.

Pityriasis rosea is a type of skin rash. It starts with one large round or oval scaly patch called the herald patch, and then causes many more small patches. The rash most often appears on the chest, back, and belly. It can take 1 to 2 months to go away. But once it’s gone, it doesn’t come back.

How to say it

pit-er-EYE-ah-sis RO-zee-ah

What causes pityriasis rosea?

The cause is not yet known but experts think it may be from a virus. The rash happens most often in people ages 10 to 35, and in pregnant women. If you are pregnant, make sure to tell your healthcare provider about your rash.

Symptoms of pityriasis rosea

In some people, the rash shows up 1 to 2 weeks after symptoms such as headache, sore throat, nausea, stuffy nose, and fever. The rash often starts with one large scaly patch in the shape of a circle or oval. The patch may be pink or red if you have pale skin. It may be purple, brown, or gray if you have darker skin. It can be 1 to 2 inches wide or larger. It usually appears on the chest or back. This is called a herald or mother patch.

Smaller patches then show up in 1 to 2 weeks on the chest, back, belly, arms, and legs. It can also show up on the neck and face. The rash can form the shape of a Christmas tree on your back. The patches may itch, especially if your skin gets warmer during exercise or a hot shower. You may also feel tired and achy.

Treatment for pityriasis rosea

The rash should go away without treatment, but it can take 4 to 8 weeks or longer. Once the rash goes away, it doesn’t come back.

You can treat your itching with any of these:

  • Corticosteroid cream or ointment. You can apply this medicine to the rash 2 to 3 times a day, for up to 3 weeks.

  • Calamine lotion. This is a pink, watery lotion that can help stop itching.

  • Antihistamine. This medicine can help reduce itching. You can put it on the skin as a cream or take it by mouth as a pill.

  • Other anti-itch lotion or cream. Ask your healthcare provider about other anti-itch lotion or cream that can help relieve itching. He or she may prescribe a stronger medicine if drugstore medicine isn’t helping you.

If you have severe symptoms, your healthcare provider may treat you with any of the below:

  • Prednisone. This is an oral steroid medicine. It can help relieve severe itching if needed.

  • Acyclovir. This is a type of anti-virus medicine. It may help the rash go away sooner in some people.

  • Ultraviolet light treatment. Exposing the skin to ultraviolet light in the first week can help lessen symptoms.

When to call your healthcare provider

Call your healthcare provider right away if you have any of these:

  • New symptoms

  • Rash that lasts for more than 3 months

  • Symptoms that don’t get better in 1 to 2 months, or get worse