Pitryiasis rosea is a somewhat common distinctive looking rash with a self-limited course that predominantly affects children and young adults. It typically starts with a large oval to round salmon-red patch with a fine, wrinkled tissue like scale trailing behind the border.
Within one to two weeks of this “herald patch”, smaller, similar oval shaped lesions erupt over the trunk and proximal extremities. Numerous lesions on the back sometimes give the characteristic drooping pine tree or “Christmas tree distribution”.
PR is now felt in most cases to be a reactivation of a childhood virus. The rash is typically asymptomatic and clears in about 6-8 weeks on its own. Occasionally it can last longer, and itching can become more prominent with more extensive involvement. It also can be misdiagnosed as other similar appearing skin conditions and mistreated; so consultation with a Dermatologist can be reassuring