Pityriasis rosea is a common type of skin rash seen in young adults.
Causes
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 be highly contagious.
Attacks generally last 4 - 8 weeks. Symptoms may disappear by 3 weeks or last as long as 12 weeks. There is generally a single large patch (herald patch) followed several days later by a rash.
Centers have wrinkled (cigarette paper) appearance
Lesions appears like a scale that is attached at the edges and loose at the center
May follow cleavage lines or appear in a "Christmas tree" pattern
May spread
Oval plaque, papule, or macule
Sharp border (edge)
Starts with a single (herald) lesion followed several days later by more lesions
Skin redness or inflammation
Exams and Tests
Your health care provider can usually diagnose pityriasis rosea by the way the rash looks. A blood test may be needed to rule out a form of syphilis, which can cause a similar rash. Occasionally, a skin biopsy may be needed to confirm the diagnosis.
Treatment
If symptoms are mild, no treatment may be needed.
Gentle bathing, mild lubricants or creams, or mild hydrocortisone creams may be used to soothe inflammation. Antihistamines, taken by mouth, may be used to reduce itching.
Moderate sun exposure or ultraviolet light treatment may help make the lesions go away more quickly. However, care must be taken to avoid sunburn.
Outlook (Prognosis)
Pityriasis rosea usually goes away within 6 - 12 weeks. It doesn't usually come back.
When to Contact a Medical Professional
Call for an appointment with your health care provider if you have symptoms of pityriasis rosea.
References
Habif TP. Psoriasis and other papulosquamous diseases. In: Habif TP, ed. Clinical Dermatology. 4th ed. Philadelphia, Pa: Mosby Elsevier; 2004: chap 8.
Review Date:
11/16/2008
Reviewed By:
Linda Vorvick, MD, Family Physician, Seattle Site Coordinator, Lecturer, Pathophysiology, MEDEX Northwest Division of Physician Assistant Studies, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.