The inflammatory skin disorder pityriasis rosea peaks in incidence during adolescence and young adulthood. It typically begins as a large (three-quarters of an inch to two inches in diameter) pink rash on the chest or back. This is called a “herald patch,” because it is indeed a harbinger of what is to follow.
Within one to two weeks, the youngster breaks out in dozens, if not hundreds, of smaller faint-pink rashes. The trunk, arms, legs and neck may be affected, but rarely the face. Parents often confuse pityriasis rosea with ringworm, a fungal infection. Pityriasis rosea’s cause isn’t known, but it is not a fungal infection and therefore isn’t helped by antifungal medications. One way to recognize the disorder is to examine the chest or back for the distinctive Christmas-tree-shaped pattern of its flat, oval-shaped lesions.
Pityriasis rosea presents differently in African Americans, who tend to develop raised patches on their face and extremities more so than on their torsos. The color usually differs, too: light-brown instead of pink, and with a coarse, granular center.
Symptoms That Suggest Pityriasis Rosea May Include:
Large pink patch, typically on the torso, followed by:
- Multiple smaller rashes
- Mild fatigue
- Mild itching
How Pityriasis Rosea Is Diagnosed
Physical examination and thorough medical history, plus KOH prep, in which a tiny sample of tissue from one of the spots is scraped off and examined under a microscope to rule out fungal infection.
How Pityriasis Rosea Is Treated
Pityriasis rosea is not contagious and does not pose any danger, usually running its course within three to nine weeks. Expect new spots to erupt during that time. Until the rashes fade and disappear—leaving no scars, happily—your pediatrician will focus on controlling symptoms. For example, lotions or antihistamines may be prescribed to relieve the itching. Exposure to sunlight or ultraviolet light treatments are sometimes recommended to hasten resolution of the rashes.
Helping Teenagers Help Themselves
Youngsters with symptomatic pityriasis rosea may wish to avoid strenuous physical activity, which can exacerbate existing rashes. Bathing in lukewarm water, not hot water, is also recommended.