Adult Skin Problems Slideshow Pictures Take the Skin Conditions Quiz Gallery of Skin Problems Pictures

Medical Author:

Nili N. Alai, MD, FAAD

Nili N. Alai, MD, FAAD

Dr. Alai is an actively practicing medical and surgical dermatologist in south Orange County, California. She has been a professor of dermatology and family medicine at the University of California, Irvine since 2000. She is U.S. board-certified in dermatology, a 10-year-certified fellow of the American Academy of Dermatology, and Fellow of the American Society of Mohs Surgery.

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Medical Editor:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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What is pityriasis rosea?

Pityriasis rosea is a common rash usually seen in individuals between the ages of 10 to 35 years old. The rash typically lasts six to eight weeks, rarely extending 12 weeks or longer. Once a person has pityriasis rosea, it generally does not recur in their lifetime.

Pityriasis rosea characteristically begins as an asymptomatic single, large pink patch called the "herald patch" or mother patch, measuring 2-10 centimeters. The herald patch is a dry, pink to red patch which appears on the back, chest, or neck and has a well-defined, scaly border.

One to two weeks following the initial appearance of the herald patch, a person will then develop many smaller pink patches across their trunk, arms, and legs. The second stage of pityriasis rosea erupts with a large number of oval spots, ranging in diameter from 0.5 centimeter (size of a pencil eraser) to 1.5 centimeters (size of a peanut). The individual spots form a symmetrical "Christmas tree" pattern following lines of cleavage. This rash is usually limited to the trunk, arms, and legs, rarely occurring on the face and neck. Pityriasis rosea generally spares the face, hands, and feet.

Who gets pityriasis rosea?

Pityriasis rosea is, for the most part, equally common between the two sexes, although there is a slightly higher occurrence reported in women. It generally occurs in children and young adults between 10-35 years of age. Pityriasis rosea has no racial predominance. Most people only get pityriasis once in their lifetime, although it is theoretically possible to have it more than once.

What are signs and symptoms of pityriasis rosea?

Most people do not notice any symptoms with pityriasis rosea except for the appearance of the rash itself. Mild, intermittent itching is reported in about 50% of individuals affected, especially when people become overheated from exercise or hot showers. Itching seems to increase with stress. Sometimes pityriasis is accompanied by flu-like symptoms, such as sore throat, fatigue, nausea, aching, and decreased appetite. Most people are otherwise in very good health and don't feel any other symptoms.