Pityriasis rosea

Pityriasis rosea is a skin rash that usually appears on your upper body and/or your upper legs.

Key points

  • Pityriasis rosea sometimes follows a viral illness that can include a cough, sore throat, runny nose and body aches.
  • It is thought that pityriasis rosea is caused by the body’s reaction to a viral illness.
  • It most often affects teenagers and young adults, between the ages of 10 to 35 years. 
  • Although there are no long-term medical concerns, pityriasis rosea can reoccur if you are run down or have a viral illness again later in life.
  • Pityriasis rosea is not contagious which means that it cannot be spread from person-to-person. There is no need to keep children away from school.

What are the symptoms of pityriasis rosea?

Pityriasis rosea usually starts with a single pink or red oval patch from 2cm up to 10cm (rarely) in size. This is called a herald patch (early sign).

About 7 to 14 days after the appearance of the herald patch, areas of pink or red flaky rash can appear. This rash occurs mostly on the upper body and forms a t-shirt shape. 

  • Infants and young children may have a rash that looks like blisters (vesicular rash)  
  • Young children, pregnant women and people who have dark skin may experience rounded bumps (papular rash)

In about 1 in 4 cases, you will also get itching along with the rash. Some people have no itching at all while others have severe discomfort.

The rash usually lasts a few weeks or, in bad cases, a couple of months. In most cases, the rash completely heals and there are no ongoing medical concerns. As the rash clears up, patches of lighter skin can appear, but this usually disappears over time.

You may have a mild headache and feel unwell just before the rash comes up, or even when the rash is present.

How is pityriasis rosea diagnosed?

Pityrasis rosea is usually harmless, but you should visit your doctor to make sure that the rash is not another skin condition such as ringworm, which is contagious.

It’s particularly important to see your doctor if you get a rash on the palms of your hands or the soles of your feet, as this can be a sign of something more serious than pityriasis rosea.

What is the treatment for pityriasis rosea? 

Self-care

Shower and bathe with plain water and bath oil, aqueous cream, or other soap substitutes. Normal soap can irritate the rash. Use lukewarm water – avoid taking hot baths or showers as this can also irritate the skin. You can apply moisturising creams to dry skin. Read more about emollients & moisturisers.

If the rash is itchy, it is important not to scratch, as sometimes a scratch-itch cycle can develop. This happens when you itch more because you scratch, so you scratch more because you itch and so on.

Direct sunlight may heal the rash more quickly, but it is important not to get sunburnt, so keep covered up.

Medication­­

Usually no medication is required for pityriasis rosea as it goes away by itself. If you have an itchy rash, your doctor or pharmacist may prescribe antihistamines to calm your body’s immune system down and try to reduce the itch.

Mild steroid creams such as hydrocortisone can also provide relief from itching. 

Learn more

DermNet NZ              

References

  1. Pityriasis rosea DermNet NZ, 2014
  2. Pityriasis rosea British Association of Dermatologists, 2011
Credits: Health Navigator Editorial Team. Last reviewed: 08 May 2017