Pityriasis rosea is a childhood skin problem that is extremely common. It is also known as “the Christmas tree rash”. It is not related to rosacea, which is a chronic, incurable problem with the skin that usually affects adults. Few people know about pityriasis rosea. It results in patches of red on the skin and flaking of the skin. There are several pityriasis rosea stages that are identifiable by the findings on the skin.
What Is Pityriasis Rosea?
Pityriasis rosea is characterized by red lesions on the skin bordered by areas of skin that peel off in little scales. It is an extremely common skin condition and is completely benign. It was first identified by Camille Gilbert, who was a French physician dating back to about 1860. It has papulosquamous lesions that look like tiny, raised papules and scaly areas to the skin. Pityriasis rosea starts in 60 percent to 90 percent of individuals with a herald patch, which is a salmon-colored or pinkish brown lesion that usually shows up on the neck, back, or chest.
Causes of Pityriasis Rosea
No one knows the exact cause of pityriasis rosea; it may be because of a virus. Many scientists believe that pityriasis rosea is a viral infection but no real viral pathogen has ever been found. There are several reasons why it is believed to be viral. Many sufferers have nonspecific and vague symptoms that precede the rash. This is one of the pityriasis rosea stages that occurs before any rash can be seen. It also appears to occur in clusters, suggesting a viral origin. While it is believed to be viral in origin, doctors don’t believe that it is particularly contagious.
It may be related to an autoimmune disease, according to some scientists. When an autoimmune disease is believed to have occurred, the body makes antibodies against healthy, normal tissue for reasons that are not completely clear.
Pityriasis Rosea Stages and Diagnosis
There are 3 stages of pityriasis rosea, each of which has different symptoms. Not everyone experiences all three stages.
1. Preliminary Signs and Symptoms
A few people with the disease will feel sick about a couple of days and up to two weeks prior to the appearance of the rash on the skin. Some of these signs and symptoms include the following:
- Indigestion or belly pain
- A fever of greater than 100.4 degrees Fahrenheit (38 degrees Celsius)
- A moderate headache
- A loss of appetite
- Pain in the joints
These symptoms usually abate by the time the rash begins to show up.
2. The Herald Patch
This is a pityriasis rosea stage in which a large pink or salmon-colored patch shows up on the back, chest, or neck. It starts out as an oval lesion that grows over a few days’ time. It can be as little as 2 centimeters in diameter or as great as 10 centimeters in diameter (0.8 to 4 inches). The patch usually shows up in the areas mentioned above; however, it can appear on the scalp, face, or genitals.
3. Rash Stage
After the herald patch comes the rash. It comes on a few days to a couple of weeks after the herald patch shows up. It can last up to six weeks.
This type of rash is usually comprised of small, raised, and scaly patches that are about 0.5 to 1.5 centimeters in length. They occur primarily on the back, chest, neck, upper arms, belly, and upper thighs. It does not affect the face.
In people who have light-skin, the patches tend to be reddish or pinkish in color. In dark-skinned people, the patches can be dark brown or gray in color. Some patches are black. They form a “Christmas tree pattern” on the chest or back with all the patches spreading out from the center. The rash doesn’t have to be painful but in many cases, it can itch. It can be mildly itchy or severely itchy. If you sweat or wear tight clothing, the itching is usually worse.
Usually, the herald patch and the other skin patches will dissipate after 12 weeks, although it can take as many as five months before they disappear. After the rash dissipates, you may have areas of dark or lightness of the skin that take months to disappear. It rarely causes a scar.
The Diagnosis of Pityriasis Rosea
There is no blood or skin test that shows that you have pityriasis rosea. You basically have to follow the pityriasis stages and take a careful history and physical examination of the skin. In the early pityriasis rosea stages, the doctor may perform biopsies or blood tests in order to see if the rash is from pityriasis rosea or if it is from some other kind of skin disease. Usually the herald patch gives away the fact that the disease is pityriasis rosea.
Treatment of Pityriasis Rosea
The basic treatment of pityriasis rosea is to manage the symptoms and support the itching and other symptoms. Even if nothing is done in the way of treatment, the condition usually resolves itself within 1 to 3 months. Much of the treatment of the disease is related to reducing the level of itching the person is experiencing. This can involve steroid creams applied to the skin, the use of ointments for itching, and oral antihistamines.
There have been various treatments that doctors have used to shorten the time that the rash is present. These therapies can involve giving antiviral medications such as acyclovir or famcyclovir, giving the antibiotic known as erythromycin, or providing the patient with systemic corticosteroids. While they are often given, research does not support their effectiveness against pityriasis rosea.
Another treatment that sometimes works is phototherapy. It is often used for people who have some type of inflammatory skin disease like pityriasis rosea. It can be given alone or along with a variety of topical remedies. Some people get better if they expose the rash to the sun.