Symptoms of pityriasis rosea
Pityriasis rosea can affect anyone, but it's more common in older children and young adults (aged 10 to 35). Figures from the National Institute for Health and Care Excellence (NICE) show around 1 or 2 in every 100 people develop the condition each year.
The symptoms include:
Some people feel unwell for a few days before they get the rash, with symptoms such as a headache, fever and joint pain.
The herald patch
A single pink or red oval patch of scaly skin, known as the "herald patch", usually appears at least two days before a more widespread rash develops.
It ranges in size from 2cm to 10cm. It can appear on your tummy, chest, back or neck, and less commonly on the face or scalp, or near your genitals.
A few days to two weeks later, a more widespread rash develops, which may continue to spread over the following 2 to 6 weeks.
It consists of smaller raised scaly patches that usually range in size from 0.5cm to 1.5cm. Most people get many patches across their chest, back, tummy, neck, upper arms and upper thighs. The face is usually unaffected.
In light-skinned people, the patches are usually a pinkish-reddish colour. In dark-skinned people, the patches can sometimes be grey, dark brown or black.
The rash isn't painful, but it can sometimes be itchy.
Both the herald patch and rash usually last for 2 to 12 weeks, although they can last for up to 5 months.
After the rash has gone, you may have some darker or lighter areas of skin. These should return to normal within a few months and won't leave permanent scarring.
When to see your GP
If your GP is uncertain, they may refer you to a skin specialist (dermatologist).
Treating pityriasis rosea
Creams and medication can help reduce, or prevent symptoms, until the condition clears up.
If the symptoms are severe and not responding to treatment, your GP may refer you to a dermatologist (hospital doctor who specialises in treating skin conditions).
Causes of pityriasis rosea
It's not known what causes pityriasis rosea. One theory is that the rash may be caused by a viral infection.
Pityriasis rosea isn’t contagious. It can't be spread to other people through physical contact.
Pityriasis versicolor is another common skin condition that can be confused with pityriasis rosea, as the rash may look similar.
But there are important differences between the two. Pityriasis versicolor is caused by a yeast infection and can be treated with antifungal medicines, including antifungal creams and antifungal shampoos.