Pityriasis Rosea
Introduction
Pityriasis rosea (pi-tuh-rai-uh-suhs row-zee-uh) is a common rash that usually affects older children and young adults. It usually begins with a ‘herald’ patch on the skin – a large 2 to 10cm oval or circular red patch. This is then followed by smaller patches 2 weeks after the initial patch. These usually occur over the chest and back, though sometimes can occur on the thighs, upper arms, neck, face and scalp. The rash usually lasts for 6 to 8 weeks and will resolve on its own.
Who gets it?
Pityriasis rosea usually occurs in those aged between 10-35 years.
It occurs equally in boys and girls and can affect all races.
What causes it?
The exact cause of the rash is unknown. Viral cause is most likely but the exact virus has not been identified. In some cases there have been medications and vaccinations that seem to be linked to the rash but this is also not proven.
It is not believed to be contagious.
What does it look and feel like?
Looks like…
Usually the rash will be red or tan in colour and scaly.
It usually begins as a large, single, circular or oval patch, with some scaling on the edge.
Smaller scaly patches appear 1 to 2 weeks after the initial patch.
Usually the patches are on the back, torso and upper arms and thighs, arranged over the ribs and skin creases giving the appearance of a Christmas tree.
It doesn’t usually affect the face, scalp, palms or soles.
Feels like…
Dry, flat patches of skin which can sometimes be thickened
Can be very itchy, but in most cases doesn’t itch at all
Flu-like symptoms (fever, headache, muscle ache, sore-throat, tiredness) can be present in your child before the initial skin rash appears
What tests might be needed?
Usually history and examination is all that is required to diagnose pityriasis rosea. However, sometimes it can be mistaken for psoriasis or a fungal skin infection like ringworm. In these instances, a sample of the skin may be taken (biopsy) or some scraping of the skin is performed.
What treatments are available?
What can I do?
Usually no treatment is required to treat pityriasis rosea and it will resolve on its own over time. However treatments to manage itch, skin irritation and reduce the duration of the rash include:
Moisturising creams
Cool compresses and baths
Oral antihistamines
Steroids creams
Phototherapy (UVB) or exposure to natural sunlight (early morning or late afternoon sunlight to avoid sunburns)
Antiviral medications
What happens after treatment?
Pityriasis rosea clears on its own after 6 to 8 weeks.
It leaves no permanent marks or scars on the skin. In some cases darker or lighter coloured skin patches may be present for weeks to months after the rash disappears. This is known as post inflammatory dyspigmentation and is more likely in darker skinned children.
Rarely, children who have had pityriasis rosea, may develop it again in their lifetime.
What support is available?
If these patches last longer than 3 months, it is best to see your local GP who may refer your child to a dermatologist as they may have another skin condition.
Authors/Reviewers:
Author: Dr Beverly Manago
Paediatric Reviewer: Dr Mayuri Sivagnanam
Editor in Chief: Dr Tevi Wain