Pityriasis rosea

Definition:

A skin disorder involving characteristic rash.

Causes, incidence, and risk factors:

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. There is generally a single larger patch called a herald patch followed several days later by more rash. Although the disorder usually resolves in time, a health care provider should be consulted to rule out other disorders including syphilis.