Pityriasis Rosea
Pityriasis rosea is a self-limited, benign skin eruption which frequently affects young adults. Commonly a single patch resembling ringworm may appear days before other lesions start to rapidly spread. This initial lesion is referred to as the "herald patch." The individual lesions are usually oval, tan to pink, slightly scaly, and sometimes mildly itchy. They generally appear on the trunk, upper arms, and thighs, and are often arranged in a “Christmas tree” pattern on the back, but can be in other patterns.
A normal course of pityriasis rosea may extend 6 to 8 weeks, but leaves no residual scarring. Continuing new lesions after two months should be reevaluated by a clinician.
Other rashes that may appear like pityriasis rosea include drug reaction rashes or the rash of secondary syphilis. In the latter case, a single blood test may be necessary.
The cause of pityriasis rosea is unknown, although a viral origin is suspected. A higher incidence of pityriasis rosea is noted in the fall, winter, and early spring months. The rash does not seem to be highly contagious. Often only one family or group member contracts pityriasis rosea.
Treatment consists mainly of keeping the skin moisturized and relieving the itching, if present. Drying soaps may irritate the skin and cause itching. Use mild or superfatted soaps such as, White Dove, Oil of Olay, Cetaphil, Basis, or Aveeno.
Avoid hot showers, as heat brings out itching. Topical medications such as anti-itch lotions may be helpful. In cases of severe itching, steroid creams and/or ultraviolet light treatments may be prescribed by a clinician.
