Pityriasis rosea (pit-uh-rahy-uh-sis row-zee-ah) is a common skin disease that causes a rash. This rash usually disappears on its own without treatment. You can expect to see the rash for about 6 to 8 weeks. Sometimes the rash lasts much longer.
This rash can be very itchy.
Some people who develop this rash see a dermatologist to get treatment for the itch.If this rash appears during pregnancy, a woman should tell her doctor.
No one knows what causes pityriasis rosea. Research shows that it is not an allergy. We also know that fungi (plural of fungus) and bacteria do not cause this skin disease. A virus may be the cause, but researchers have yet to prove this.
It is possible that a virus causes pityriasis rosea, but this skin disease does not seem to be contagious. It does not seem to spread from one person to another.