RASH OF PITYRIASIS ROSEA USUALLY CLEARS UP IN A MATTER OF WEEKS

Question: About six weeks ago, I got diagnosed with pityriasis rosea, and it is starting to itch really bad. Do you think it would be good for me to get a steroid shot or take medicine internally? Would this reduce the itching and help make it go away more quickly?

Answer: Pityriasis rosea is a fairly common rash, especially in young women. It usually occurs in the spring and fall. It is probably of viral origin and is not highly contagious. It can be associated with other viral type symptoms such as headache, fatigue and malaise, but this is relatively uncommon.

The rash starts out with a single lesion usually on the trunk. It is a large oval patch (the “Herald Patch”) that’s flat (no elevation of the skin). This patch has dark red borders and is clear in the center. It is painless and doesn’t itch. One to two weeks later, a generalized rash appears, also on the trunk. These are small, oval, fawn-colored flat patches. They appear scaly on the edges and clear in the center. The rash is often asymptomatic, but can be itchy -- as in your case. The rash follows the cleavage lines of the skin and has a “Christmas Tree” appearance down the back. Generally no treatment is necessary, and the rash disappears in six to eight weeks. On rare occasions, the rash has been known to take over two months to clear up.

As for your itching, using a topical steroid cream can help as well as taking Benadryl by mouth. Benadryl can cause some drowsiness, so use it with caution. A unique feature of this rash is that it can be helped by ultraviolet light, so getting out in the sun or using UVB light daily for about a week can be a big help. In severe cases, your doctor may recommend the use of systemic corticosteroids -- either by mouth or injection. Since this rash is self-limiting and rarely recurs, your doctor will only consider steroids as a “last resort.”

While pityriasis rosea is usually a rather straight- forward diagnosis, rashes can sometimes be difficult to identify as many of them look alike. For instance, your doctor may make a skin scraping of a lesion to rule in or rule out fungal rashes that look very similar to pityriasis rosea. Blood tests to check for possible systemic illnesses are also indicated in some cases. Finally, there are some medications that can cause rashes similar to pityriasis rosea that your doctor must rule out. Having said all this, let me repeat that a medical professional can easily diagnosis a classic case of pityriasis rosea just by looking at the tell-tale rash.

"Family Medicine" is a weekly column. To submit questions, write to Martha A. Simpson, D.O., M.B.A., Ohio University College of Osteopathic Medicine, P.O. Box 110, Athens, Ohio 45701. Past columns are available online at http://www.FamilyMedicineNews.org.