Pityriasis rosea is a common type of skin rash seen in young adults.
Pityriasis rosea is believed to be caused by a virus. It occurs most often in the fall and spring.
Although pityriasis rosea may occur in more than one person in a household at a time, it is not thought to spread from one person to another.
Attacks most often last 4 to 8 weeks. Symptoms may disappear by 3 weeks or last as long as 12 weeks.
The rash starts with a single large patch called a herald patch. After several days, more skin rashes will appear on the chest, back, arms, and legs.
The skin rashes:
Your health care provider can usually diagnose pityriasis rosea by the way the rash looks.
Rarely, the following tests are needed:
If symptoms are mild, you may not need treatment.
Gentle bathing, mild lubricants or creams, or mild hydrocortisone creams may be used to soothe irritation.
Antihistamines taken by mouth may be used to reduce itching. You can buy antihistamines at the store without a prescription.
Moderate sun exposure or ultraviolet (UV) light treatment may help make the rash go away more quickly. However, you must be careful to avoid sunburn.
Pityriasis rosea usually goes away within 6 to 12 weeks. It doesn't usually come back.
Call for an appointment with your health care provider if you have symptoms of pityriasis rosea.
Habif TP. Psoriasis and other papulosquamous diseases. In: Habif TP, ed. Clinical Dermatology. 5th ed. Philadelphia, PA: Elsevier Mosby;2009:chap 8.
Pityriasis rosea. Alvero R, Ferri FF, Fort GG, et al, eds. In: Ferri FF, ed. Ferri's Clinical Advisor 2015. 1st ed. Philadelphia, PA: Elsevier Mosby; 2014:section I.
Last reviewed on: 11/2/2014
Reviewed by: Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.