What is pityriasis rosea?
Pityriasis rosea is usually harmless.
What causes pityriasis rosea?
The rash does not appear to spread from person to person.
What are the symptoms?
Pityriasis rosea causes a rash.
- 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. See a picture of a herald patch .
- 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.
- Mild itching is a problem for about half of the people who get the rash.
- The rash usually lasts 6 to 8 weeks, but it can last up to several months.
In rare cases, the rash may take other forms. Rounded bumps (papular rash) may be seen in young children, pregnant women, and people who have dark skin. Blisters (vesicular rash) may be seen in infants and young children. In some people, the herald patch may not appear, or two herald patches may appear close together.
If you get a rash on the palms of your hands or the soles of your feet, see your doctor. This can be a sign of something more serious than pityriasis rosea.