Pityriasis rosea is a mysterious condition which erupts on the skin, lasts a short period, and disappears. It is unsightly and may itch, but it does no harm. Its characteristics are:
The cause of pityriasis rosea is unknown, but a virus is considered the most likely culprit. The condition occurs in a certain age group, erupts suddenly, lasts a certain length of time, clears completely, and rarely occurs again in the same individual. There is also a slight "epidemic" quality to the occurrence of pityriasis rosea; it is more frequent in the spring and autumn. However, against a viral cause of this disease is the fact that it is not contagious (it is rarely seen in family or school groups), and no viruses have been found.
There is no treatment that shortens the duration of pityriasis rosea. Ultraviolet light temporarily suppresses or heals some of the rash, but effective treatment with it is impractical. Itching is usually sporadic and mild. When it is bothersome it can be soothed by Aveeno Oatmeal baths, moisturizing lotions or creams (like Vaseline Intensive Care lotion, Lubriderm lotion, Eucerin cream), or cortisone creams (like 1% hydrocortisone cream, Kenalog cream). Antihistamine pills (like Benadryl 25-50 mg every 6 hours, or chlorpheniramine 4 mg every 4-6 hours) may relieve itching but often cause drowsiness, so they are best used at bedtime.
All in all, the appearance of pityriasis rosea is at first alarming, but you can take comfort in the knowledge that it will not last long, it will not harm internal organs or leave scars, it is not contagious, and it is unlikely to recur.