What is pityriasis rosea?

Pityriasis rosea is a mild skin rash with a pink, scaly and inflamed appearance. The condition is quite common, and it is not serious. It is most common in young adults.

The rash usually lasts between 1 to 3 months and leaves no permanent marks. However, people with dark skin may notice lasting brown spots after the rash has healed.

Once it is gone, it usually does not come back.

What are the symptoms of pityriasis rosea?

The first sign is usually a circular or oval patch on the chest, belly or back. The patch is usually pink or tan.

Over the next couple of weeks, smaller pink or tan patches appear on areas such as the back, neck, arms or legs. The pattern of these patches can look like drooping pine-tree branches.

You may also notice that you:

• feel tired
• have aches and pains
• are itchy, sometimes severely
• have a cold, sore throat or fever before the rash develops

Pityriasis rosea on a person's abdomen

Close-up of pityriasis rosea on skin

What causes pityriasis rosea?

The cause of pityriasis rosea is not known but it is thought to be caused by a virus or bacteria. It is probably not contagious.

How is pityriasis rosea diagnosed and treated?

Doctors can usually diagnose the rash of pityriasis rosea just by looking at it.

Your doctor may take a scraping for testing or do a blood test to rule out other conditions.

Most treatments for pityriasis rosea aim to soothe the skin and relieve itching. They include:

• corticosteroid cream or ointment, which may also decrease redness
• using a gentle soap-free wash
• using moisturiser

If you have pityriasis rosea, avoid having a hot bath or sauna, as heat can make the itching worse. Contact your doctor if the rash gets worse, it gets swollen or infected, or it does not go away in 8 weeks.

It is very unusual for the rash to come back.

Natural or artificial sunlight can help fade the rash, but in some people this can cause lasting dark patches.

If you develop pityriasis rosea when you are pregnant then check with your doctor, as in rare cases it can lead to complications.