What is Pityriasis rosea?
Pityriasis rosea (say “pih-tih-RY-uh-sus ROH-zee-uh”) is a common skin problem that causes a rash. Although it can occur at any age, it is seen most often in those between the ages of 10 and 35.
Pityriasis Rosea Facts
- Pityriasis rosea – This common skin disease causes patches on the skin. Your dermatologist may call the large patch a mother patch. The smaller patches are daughter patches.
- Pityriasis rosea (pit-uh-rahy-uh-sis row-zee-ah) is a common skin disease that causes a rash. This rash usually disappears on its own without treatment. You can expect to see the rash for about 6 to 8 weeks. Sometimes the rash lasts much longer.
- Pityriasis is a common skin problem that causes a rash. Although it can occur at any age, it is seen most often in those between the ages of 10 and 35.
- Pityriasis rosea is usually harmless. But it can cause serious problems in pregnant women.
Symptoms of Pityriasis rosea
- The rash often begins with a single, round or oval, pink patch that is scaly with a raised border (herald patch). The size of the patch ranges from 2 cm (0.8 in.) to 10 cm (3.9 in.). The larger patches are more common.
- Days to weeks later, salmon-colored, 1 cm (0.4 in.) to 2 cm (0.8 in.) oval patches appear in batches on the abdomen, chest, back, arms, and legs. Patches sometimes spread to the neck but rarely to the face.
- Patches on the back are often vertical and angled to form a “Christmas tree” or “fir tree” appearance.
- The rash does not cause itching in 25% of people who have pityriasis rosea. For 50% of people, the itch is mild to moderate. And for 25% of people, the itch is severe.1
- The rash usually lasts 6 to 8 weeks, but it can last up to several months.
Causes of Pityriasis rosea
The exact cause of pityriasis rosea is unclear, although there is some evidence that the rash may be triggered by a viral infection, particularly by certain strains of the herpes virus. Pityriasis rosea, however, isn’t believed to be contagious.
Complications of Pityriasis rosea
Complications of pityriasis rosea aren’t likely, but if they do occur, they may include:
- Severe itching
- Lasting brown spots after the rash has healed, on dark skin
How long does pityriasis rosea last?
Pityriasis rosea clears up in about six to twelve weeks. Pale marks or brown discolouration may persist for a few months in darker skinned people but eventually the skin returns to its normal appearance.
Second attacks of pityriasis rosea are uncommon (1–3%), but another viral infection may trigger recurrence years later.
What is the treatment for pityriasis rosea?
Pityriasis rosea usually requires no treatment and resolve spontaneously. Treatment is not necessary if the rash does not cause significant problems. Typically, pityriasis rosea will usually clear on its own in nine weeks without medical intervention or therapy.
The most common symptom is itching, which can be treated with topical steroid creams (like hydrocortisone cream) and oral antihistamines. These will not shorten the duration of the rash but will decrease the itching. Another treatment for itching is UVB light or sunlight. However, exposure to sunlight increases the risk of skin cancer. Generally, the best treatment is to avoid being overheated by reducing exercise and avoiding hot showers and baths.
There has been some evidence of reduced duration of pityriasis rosea with the off-label use of the antibiotic erythromycin or off-label use of antiviral medications such as acyclovir or famciclovir . However, neither of these medications has been proven to be uniformly effective in the treatment of pityriasis rosea and they are not usually necessary or required.