Pityriasis rosea may be caused by a viral infection.
The most common symptoms are itching and an initial large, tan-colored or rose-colored circular patch that is followed by multiple patches that appear on the torso.
The diagnosis is based on symptoms.
This disease usually resolves with no treatment, and itching that is not severe may be alleviated with artificial or natural sunlight.
The cause of pityriasis rosea is not certain, but an infection with human herpesvirus type 6, 7, or 8 may be involved. However, the disorder is not thought to be contagious.
Some medications (for example, ACE inhibitors, hydrochlorothiazide, captopril, barbiturates, metronidazole, and allopurinol) may cause a reaction that looks like pityriasis rosea.
Pityriasis rosea most commonly occurs in people between the ages of 10 and 35 years. Pityriasis rosea affects women more often than men.
Women who develop pityriasis rosea during pregnancy (especially during the first 15 weeks of gestation) may have a premature Preterm (Premature) Newborns A preterm newborn is a baby delivered before 37 weeks of gestation. Depending on when they are born, preterm newborns have underdeveloped organs, which may not be ready to function outside of... read more or stillborn Stillbirth Stillbirth is death of a fetus after 20 weeks of pregnancy. Stillbirth may result from a problem in the woman, placenta, or fetus. Doctors do blood tests to try to identify the cause of a stillbirth... read more baby.
Symptoms of Pityriasis Rosea
Pityriasis rosea at first causes a single rose-colored or tan-colored round patch of skin about 1 to 4 inches (2 to 10 centimeters) in diameter. Doctors call this first patch a herald or mother patch. This patch usually develops on the torso.
In 7 to 14 days, many similar but smaller, scaly patches appear on other parts of the body. These secondary patches are most common on the torso, especially along and radiating from the spine.
The patches may appear more rose or tan in color in people with light skin and may appear more purple in people with dark skin.
In children, the patches commonly begin in the groin or underarms and spread outward. Children and pregnant women may have little or no scaling.
Most people with pityriasis rosea have some itching, and in some people the itching can be severe.
Sometimes the patches appear without any previous symptoms, but some people have a vague feeling of illness, loss of appetite, fever, headache, and sometimes joint pain a few days before the patches appear.
Diagnosis of Pityriasis Rosea
A doctor's evaluation
A doctor usually makes the diagnosis of pityriasis rosea based on the appearance of the rash, particularly the herald patch.
Treatment of Pityriasis Rosea
For itching, artificial and natural sunlight or topical corticosteroids
Both artificial and natural sunlight may speed up clearing and relieve the itching.
Other standard treatments for itching may be used as needed (see treatment of itching Treatment Itching can be very uncomfortable. It is one of the most common reasons people see doctors who specialize in skin disorders (dermatologists). Itching makes people want to scratch. Scratching... read more ). Corticosteroids applied directly to the skin (topically) can also be used for short periods to help relieve itching.
Corticosteroids taken by mouth are necessary only for very severe itching.
The antiviral medication acyclovir may help some people whose illness is in an early stage and who have many patches or may help people who have flu-like symptoms. Pregnant women with pityriasis rosea should be offered acyclovir, but treatment with this medication does not reduce the risk of premature birth or stillbirth.
Prognosis for Pityriasis Rosea
Usually the rash goes away within 5 weeks without treatment, although sometimes it lasts for 2 months or more.