What is pityriasis rosea?
Pityriasis rosea is a skin rash. This rash usually affects people between the ages of 6 and 35 years of age. Usually a healthcare provider needs to examine the rash to diagnose it.
The rash has the following features:
- The rash begins with a large, scaly, pink patch on the chest or back, which is called a "herald" or "mother" patch. It looks like a large ringworm and is 1 to 3 inches across.
- A widespread rash of smaller matching spots on both sides of the body occurs 7 to 14 days after the herald patch first appears.
- This rash consists of pink, oval-shaped spots that are 1/4 to 1/2 inch across. The spots are covered with fine scales, which give the rash a crinkled appearance.
- The rash appears primarily on the chest, abdomen, and back. Often it is worse in the groin and armpits. Usually the rash does not appear on the face.
- The rash can be itchy during the first one or two weeks.
What is the cause?
The cause is unknown. It is not caused by a fungus, a bacteria, or an allergy. The rash is probably caused by a virus.
How long does it last?
This condition is harmless. The rash disappears without treatment. The different parts of the rash last from 6 to 10 weeks. During this time your youngster will feel fine.
How is it treated?
- Skin creams
Treatment will reduce symptoms. It will not cure pityriasis rosea. If the skin is dry, a moisturizing cream may be helpful. For itchiness, use 1% hydrocortisone cream (no prescription necessary) 2 or 3 times a day. If the rash still itches after using this cream, call your healthcare provider's office for a stronger steroid cream.
- Sunlight exposure
One dose of ultraviolet light can stop itching and shorten the course of pityriasis. Have your youngster sunbathe for 30 minutes (enough to make the skin pink). Do this only once. If this is impossible, use a sun lamp or consider a tanning salon once. CAUTION: Avoid sunburn.
Pityriasis is not contagious. Your child can attend school and take gym.
When should I call the doctor?
Call your child's doctor during office hours if:
- The rash becomes very itchy.
- The rash becomes infected with pus or draining scabs.
- The rash lasts longer than three months.
- You have other questions or concerns.
Written by B.D. Schmitt, MD, author of "Your Child's Health," Bantam Books.
Published by RelayHealth.
Last modified: 2009-06-19
Last reviewed: 2010-06-02
This content is reviewed periodically and is subject to change as new health information becomes
available. The information is intended to inform and educate and is not a replacement for medical
evaluation, advice, diagnosis or treatment by a health care professional.