Pityriasis Rosea Overview
Pityriasis rosea (PR) is a benign, self-limiting eruption that occurs commonly in young adults or adolescents and seems to have an increased incidence during the winter months.
Cause of Pityriasis Rosea
A viral cause is suggested by its seasonal prevalence and the occasional preceding symptoms of malaise and headache. Evidence supports the role of human herpesvirus 7 (HHV-7). Up to 98 percent of affected individuals develop lifelong immunity and few experience recurrences.
Signs and Symptoms of Pityriasis Rosea
The pattern of eruption usually begins with a single, oval, pink, scaly patch several centimeters in diameter (called a herald patch). Five to 10 days later, a general eruption occurs with multiple round or oval pink patches with fine scale around the borders.
These lesions are smaller than the herald patch and sometimes erupt on the back in a Christmas tree pattern. Most lesions occur on the trunk and upper extremities, usually not on the face. New lesions form over the subsequent weeks and complete healing occurs in 2 to 3 months. Occasionally, light or dark patches remain after the rash has healed, but the skin color eventually returns to normal with no scarring.