Pityriasis Rosea is a rather common skin disease in which round or oval, scaling pink patches develop mainly on the trunk of the body, upper arms and thighs. In many cases the eruption begins with a single scaling patch (commonly called the “herald patch”), followed 1 – 2 weeks later by development of the widespread rash. The herald patch resembles ringworm, and thus is often confused with it. Pityriasis Rosea often occurs in seasonal epidemics during the Spring and Fall but may develop as an isolated case at any time. The cause of Pityriasis Rosea is not known because of it’s tendency to occur in seasonal epidemics and because of its rather predictable course. It is thought to be caused by a viral infection. If the disease is contagious at all, it is only slightly so, since multiple cases occurring at the same time within families are seen only very rarely. Pityriasis Rosea lasts from 6 – 12 weeks and then disappears leaving no scars. Since many patients are first seen in the early stage of their disease, their condition may appear to worsen considerably before it begins to improve. Typically, the eruption will peak in about 2 weeks and slowly diminish over the following month. Usually the face, forearms and hands are not heavily involved, though there are exceptions. In most persons the condition is not particularly uncomfortable or inconvenient.
No limitation of activities is required. You do not need to stay home. Treatment is for relief of symptoms only and does not alter the overall course of the disease. Sometimes the rash is itchy. In that case, a prescription anti-itch cream or lotion to be applied to the uncomfortable areas may be provided to patients. In severe cases oral antihistamines and steroids are prescribed.