Introduction Pityriasis rosea (pit-ih-RYE-ah-sis Ro-ZEA) can occur at any age but it's more common in people between the ages of 10 and 35 years. It appears as a rash which can last from several weeks to several months. Usually, there are no permanent marks as a result of this disease, although some darker-skinned persons may develop long-lasting flat brown spots. Pityriasis rosea is a common skin rash of young people, especially young adults. It is 50% more common in females. It occurs most commonly in the fall and spring, and a virus is suspected as the cause. Although pityriasis rosea may occur in more than one person in a household at a time, the disorder is no more common in married couples or large households than it is in other people. If the cause is viral, it is not thought to be highly contagious. Attacks generally last 4 to 8 weeks. Symptoms may disappear by 3 weeks or last as long as 12 weeks.

What does it look like?
Pityriasis rosea often begins with a large single pink patch of skin on the chest or back. This is usually scaly and is called a "herald" or "mother" patch. Frequently the person with pityriasis rosea will think the patch is ring-worm because of its appearance and will apply anti-fungal medications. This is not beneficial since the rash is not caused by any type of fungus. Within a week or two, a few to many smaller pink patches will occur over the trunk and, to a lesser degree, over the skin of the arms and legs. Lesions may also occur on the neck and, rarely on the face. These later-appearing spots are usually smaller than the herald patch but may still be mistaken for ring-worms. The patches often display a characteristic pattern over the back resembling the outline of an evergreen tree with drooping branches.

What are the symptoms?
Sometimes pityriasis rosea can cause a more severe skin reaction with more irritation. Itching occurs in about half of the patients with pityriasis rosea and can at times be quite severe, particularly when the patient becomes overheated. Occasionally, there may be other symptoms, including tiredness and aching. The rash usually fades and disappears within six weeks after peak activity but can sometimes last much longer. Various environmental or physical factors can cause transient worsening or even reappearance of the rash. These include physical exertion, such as running or bathing in hot water. In some cases, the patches appear in two or more waves with subsequent waves appearing at intervals of up to several weeks after the first. Additional waves sometimes appear for many months. Although the disorder usually resolves in time, Dr. Jacobs should be consulted to rule out syphilis.

What is the cause of this skin disorder?
The cause of pityriasis rosea is not known. It definitely is not caused by a fungus or bacterial infection, and it is not caused by anything that a person has eaten. It also is not due to any known type of allergic reaction, either internal or external. Pityriasis rosea is not a skin manifestation associated with any type of internal disease such as diabetes, cancer, or kidney disease. Some dermatologists have suggested that a virus may cause this rash. The reason for this is the fact that the disease is more common in young people, usually occurs only once, and occasionally makes a person feel slightly ill. This theory has definitely not been proven, and exposure to someone with pityriasis rosea essentially never causes another person to develop a rash.

Who usually diagnoses it?
The diagnosis of pityriasis rosea is usually easily made by the dermatologist, a physician with special training in skin diseases. The appearance of the rash may not be typical, however, making the diagnosis more difficult. The numbers and sizes of the spots can vary greatly and occasionally the rash can be concentrated in an unusual location, such as the lower body or on the face. Several other skin conditions are similar in appearance to pityriasis rosea. Certain skin fungus infections may resemble this rash. Also, reactions to various internal medications, such as antibiotics, fluid pills, and heart medications, may mimic pityriasis rosea. Various tests may be necessary to confirm diagnosis. The dermatologist may order blood tests, skin scrapings or even a biopsy of one of the spots to ascertain a definite diagnosis.

What is the treatment?
Treatment may include external and internal medication for itching. Only gentle, soothing measures should be used, as aggressive treatment has been known to cause the lesions to spread. If symptoms are mild, no treatment may be needed. Various types of soothing medicated lotions and lubricants may be prescribed to combat the rash. Individuals with pityriasis rosea should take lukewarm, rather than hot, baths. Soap: Soap is bad for pityriasis rosea involved skin. Dial, Zest, Lever, Safegaurd, Ivory, gels, and Irish Spring are among the worst. Soap removes skin oils needed to hold in moisture. If oils are removed, the skin develops cracks, fissures, and dry inflammation. Soap should not be used on dry or sensitive skin. Most of us use far too much soap. Actually, plain water is often just enough to cleanse the skin. If you can't live without soap, it's OK to use Dove soap for your face, feet, armpits, and groin. Avoid Allergic Items: Pityriasis rosea involved skin can become itchy when exposed to allergic type substances such as perfumes, dyes, conditioners, powders, anti-perspirants, hair sprays, grasses, plants, fragranced products, shampoos, unrinsed laundry detergents, fabric softener sheets, dog or cat hairs, carpets, chemicals, Aloe Vera, PABA, detergents, acrylic nails, polishes, nickel, elastic, latex, etc. Hair conditioners can induce itch! Please avoid perfumes. Bathing: Persons with pityriasis rosea involved skin may bathe or shower twice daily: 1. Use no soap on dry or sensitive skin areas. You may use mild Cetaphil or Aquanil soapless soaps, instead of soap. 2. After bathing, thoroughly lubricate your skin using Cetaphil Moisturizing Cream available OTC. 3. After your bath, you should not towel dry. Wipe off the water with your hands, then, apply a thin film of Cetaphil Moisturizing Cream to your entire body. This film will seal in your new moisture. 4. For shampoo, use OTC fragrance free DHS Clear Shampoo. Mild lubricants, or anti- pruritic creams, or mild hydrocortisone creams may be used all over the body to soothe the inflammation. Oral antihistamines may be used to reduce itching. Oral corticosteroids may be needed in cases of severe inflammation. Mild sun exposure may help speed resolution of lesions; however, care must be taken to avoid sunburn. Expectations (prognosis): Pityriasis rosea usually goes away within 6 to 12 weeks, but symptoms may recur. Strenuous activity may aggravate the rash. Another important feature of treatment includes reassurance to the patient by the physician that pityriasis rosea is not a dangerous skin condition.

In Summary...
Pityriasis rosea is a common, distinctive skin eruption of unknown cause. There are few symptoms. Pityriasis rosea is usually mild, but fortunately even the most severe cases respond quickly to proper treatment. Pityriasis rosea is a benign non-contagious skin disease. It can occur at any age but is more common in persons between the ages of 10 to 35 years. The rash typically lasts from several weeks to several months. It heals without scarring. There are usually no permanent marks left on the skin as a result of pityriasis rosea, although some darkly pigmented persons may have long lasting flat brown spots.