Pityriasis Rosea

Pityriasis rosea (PR), meaning rose-colored scale, is an acute self-limiting papulosquamous disorder.  Also known as pityriasis circinata, roseola annulata, and herpes tonsurans maculosus, PR is often distinguished by the development of a slightly raised, oval, scaly patch called the "herald patch." It is later followed by multiple clusters of scaly oval patches on the trunk and proximal extremities in a "Christmas tree" appearance. The skin eruption usually lasts 6 to 8 weeks and although it usually begins with a pathognomic herald patch, some cases are reported that may not exhibit this characteristic finding.