General Description
Pityriasis rosea is a common skin condition that affects people of all races and all ages, with the greatest incidence in adolescents and young adults. The disorder begins with a single oval lesion covered with a fine scale. This is called the herald patch, and it is often mistaken for a ringworm infection. A few days later, smaller patches arise especially on the chest and back. On the back, the ovoid lesions follow the skin lines and are arranged in a “fir tree” distribution. Pityriasis rosea rarely affects the face. Itching, if present at all, is usually quite minimal.
Causes
The cause of pityriasis rosea is unknown. A virus is suspected, but the condition is not considered infectious (spread to others) or contagious (caught from others). Most cases seem to occur in spring and fall.
Medical Treatments
The mainstay of treatment is a simple reassurance. The condition is a nuisance but not serious. All lesions disappear entirely within three to eight weeks. Persons with extensive patches or bothered by itching may benefit from topical steroids and/or ultraviolet light treatments. Severe cases may warrant the use of oral steroids to hasten resolution.