What is pityriasis rosea?

Pityriasis rosea: Overview

Pityriasis rosea (say "pit-uh-RY-uh-sus ROH-zee-uh") is a common skin rash. It usually starts as one scaly and pinkish, purple, or red-brown patch on your stomach or back. Days or weeks later, more small patches appear. The rash may itch, but it will not spread to other people.

Experts aren't sure what causes pityriasis rosea. It may be caused by a virus.

Pityriasis rosea is most common in children and young adults. It lasts 1 to 3 months and then goes away on its own. Medicine can help relieve any itching.

What are the symptoms of pityriasis rosea?

Pityriasis rosea causes a rash.

  • The rash often begins with a single, large, round or oval patch that is scaly with a raised border (herald patch). The patch is pink or salmon-colored on lighter skin. It is purple or red-brown on darker skin.
  • Days to weeks later, smaller oval patches appear in batches on the abdomen, chest, back, arms, and legs. Patches sometimes spread to the neck or the face.
  • In children, the rash often appears on the groin, armpit, scalp, or face.
  • Itching is common with this rash.
  • The rash usually lasts 6 to 8 weeks, but it can last up to several months.
  • After the rash, your skin may look darker. This is more common in people with darker skin. The change in color goes away with time.

Before the herald patch appears, you may feel tired and like you have a cold. You may have a headache, fever, or sore throat.

How is pityriasis rosea treated?

Pityriasis rosea usually goes away on its own without treatment. If it itches, over-the-counter anti-itch medicines may help. Other things to help with itching include staying cool, avoiding hot water, and taking oatmeal baths. Severe cases may need prescription medicines or light therapy.

How is pityriasis rosea diagnosed?

Your doctor may be able to diagnose pityriasis rosea by looking at the rash. If the diagnosis is unclear, your doctor may do a potassium hydroxide (KOH) test. This test checks to make sure the rash is not caused by a fungal infection. A skin sample may be taken from the infected area and examined under the microscope (biopsy).

In a sexually active person, a test for syphilis is often done.

How can you care for yourself when you have pityriasis rosea?

  • If your doctor prescribed medicine, use it exactly as prescribed. Call your doctor if you have any problems with your medicine.
  • Use a mild soap or a gentle skin cleanser when you wash your skin.
  • Add a handful of oatmeal (ground to a powder) to your bath. Or you can try an oatmeal bath product, such as Aveeno. Keep the water warm or lukewarm. A hot bath or shower may make the rash more visible and itchy.
  • Try an over-the-counter 1% hydrocortisone cream for small itchy areas. Use the cream very sparingly on the face or genitals. Note: Do not use the cream on children younger than age 2 unless your doctor tells you to. Do not use in the rectal or vaginal area in children younger than age 12 unless your doctor tells you to.

Pityriasis rosea

Pityriasis rosea on the back, with close-up of the rash.

Pityriasis rosea (say "pih-tih-RY-uh-sus ROH-zee-uh) is a common skin problem that causes a rash. The rash often begins with a herald patch—a single, round-to-oval, and pinkish, purple, or red-brown patch that is scaly with a raised border. Days or weeks later, more small patches often appear on the belly, chest, back, arms, and legs. Patches sometimes spread to the neck or face.

Pityriasis rosea is usually harmless.

What causes pityriasis rosea?

Experts aren't sure what causes pityriasis rosea. Unlike many other skin conditions, it is not an allergic reaction or caused by a fungus or bacteria. It may be caused by a virus.

The rash does not appear to spread from person to person.

Pityriasis rosea: When to call

Call your doctor now or seek immediate medical care if:

  • You have signs of infection such as:
    • Pain, warmth, or swelling near the rash.
    • Red streaks near the rash.
    • Pus coming from the rash.
    • A fever.

Watch closely for changes in your health, and be sure to contact your doctor if:

  • You see the rash on the palms of your hands or the soles of your feet.
  • You do not get better as expected.

©2011-2024 Healthwise, Incorporated

The content above contains general health information provided by Healthwise, Incorporated, and reviewed by its medical experts. This content should not replace the advice of your healthcare provider. Not all treatments or services described are offered as services by us. For recommended treatments, please consult your healthcare provider.