Pityriasis Rosea (PR)

Pityriasis rosea (PR) is an acute, self-limited, exanthematous skin disease felt most likely to be due to a viral etiology. The eruption commonly begins with a “herald” or “mother” patch, a single round or oval, rather sharply delimited pink or salmon-colored lesion on the chest, neck, or back, 2 to 5 cm in diameter. A few days or a week or two later, oval lesions similar in appearance to the herald patch, but smaller, appear in crops on the trunk and proximal areas of the extremities. The long axes of these oval lesions tend to be oriented along the lines of cleavage of the skin.
Most patients do not require therapy. For patients with mild itching who desire therapy, are treated with medium-potency topical corticosteroids.
For patients with severe presentations of PR who desire treatment to accelerate improvement of the skin manifestations, suggested treatment is with oral acyclovir rather than oral erythromycin. Phototherapy is an alternative treatment option.