What is pityriasis rosea?
Pityriasis rosea is a type of skin rash. It is also called
Christmas tree rash. It starts with one large round or oval scaly patch. This is
called the herald patch. It then causes many more small patches. The rash most often
appears on the chest, back, and belly. It can take 1 to 3 months to go away. But
once it’s gone, it doesn’t come back.
What causes pityriasis rosea?
Researchers aren’t sure about the cause of pityriasis rosea. But
it may be caused by a virus or bacteria. Some people may have a cold before the
Who is at risk for pityriasis rosea?
The rash happens most often in people ages 10 to 35, and in
pregnant women. If you are pregnant, make sure to tell your healthcare provider
about your rash.
What are the symptoms of pityriasis rosea?
Symptoms can occur a bit differently in each person. In some
people, the rash shows up 1 to 2 weeks after symptoms such as:
The rash often starts with one large scaly patch in the shape of a
circle or oval. This is called a herald or mother patch. The patch may be pink or
red if you have pale skin. It may be purple, brown, or gray if you have darker skin.
It can be 1 to 2 inches wide or larger. It usually appears on the chest or back.
Smaller patches then show up in 1 to 2 weeks on the chest, back,
belly, arms, and legs. It can also show up on the neck and face. The rash can form
the shape of a triangle on your back. It sometimes looks like a Christmas tree. The
patches may itch, especially if your skin gets warmer during exercise or a hot
shower. You may also feel tired and achy.
The symptoms of pityriasis rosea can be like other health
conditions. Make sure to see your healthcare provider for a diagnosis.
How is pityriasis rosea diagnosed?
Your healthcare provider will ask about your symptoms and medical
history. He or she will give you a physical exam. The physical exam will include
looking closely at the rash. You may also have tests to check for other conditions
that may look like pityriasis rosea. These tests may include:
Skin scraping. The
healthcare provider scrapes the top of your skin with a small tool. The scraped
tissue is examined with a microscope. This can show if the rash is from an
infection. This is also done because the rash can look similar to fungal
Skin punch biopsy. A small
piece of skin is cut out and removed and sent to a lab. The skin is examined for
other types of problems that may cause rash.
Blood tests. These are
done to check for infection and other problems.
How is pityriasis rosea treated?
Treatment will depend on your symptoms, your age, and your general
health. It will also depend on how severe the condition is. The rash should go away
without treatment, but it can take 1 to 3 months or longer. Once the rash goes away,
it doesn’t come back.
You can treat your itching with any of these:
Corticosteroid cream or
ointment. You can put this medicine on the rash 2 to 3 times a day, for
up to 3 weeks. This may help with itch, but it probably won’t make the rash
Calamine lotion. This is a
pink, watery lotion that can help stop itching.
medicine can help reduce itching. You can put it on the skin as a cream or take
it by mouth as a pill.
Other anti-itch lotion or
cream. Ask your healthcare provider about other anti-itch lotion or
cream that can help relieve itching. He or she may prescribe a stronger medicine
if drugstore medicine isn’t helping you.
If you have severe symptoms, your healthcare provider may treat
you with any of the below:
Prednisone. This is an
oral steroid medicine. It can help ease severe itching if needed.
Acyclovir. This is a type
of anti-virus medicine. It may help the rash go away sooner in some people if
the rash is caused by a virus.
treatment. Exposing the skin to ultraviolet light in the first week can
help lessen symptoms.
Talk with your healthcare providers about the risks, benefits, and
possible side effects of all treatments.
Can pityriasis rosea be prevented?
Researchers don’t know how to prevent pityriasis rosea.
When should I call my healthcare provider?
Call the healthcare provider if you have:
Rash that lasts for more than 3 months
Symptoms that don’t get better in 1 to 2 months, or get
You have a rash and you are pregnant
Key points about pityriasis rosea
Pityriasis rosea is a type of skin rash. It starts with one
large round or oval scaly patch. This is called the herald patch. It then causes
many more small patches.
The rash most often appears on the chest, back, and belly.
Researchers aren’t sure about the cause of pityriasis rosea.
But it may be caused by a virus or bacteria. Some people may have a cold before
The rash should go away without treatment, but it can take 1
to 3 months or longer. Once the rash goes away, it doesn’t come back.
You can treat your itching with cream, ointment, and oral
Tips to help you get the most from a visit to your healthcare
Know the reason for your visit and what you want to
Before your visit, write down questions you want
Bring someone with you to help you ask questions and
remember what your provider tells you.
At the visit, write down the name of a new diagnosis, and
any new medicines, treatments, or tests. Also write down any new instructions
your provider gives you.
Know why a new medicine or treatment is prescribed, and how
it will help you. Also know what the side effects are.
Ask if your condition can be treated in other ways.
Know why a test or procedure is recommended and what the
results could mean.
Know what to expect if you do not take the medicine or have
the test or procedure.
If you have a follow-up appointment, write down the date,
time, and purpose for that visit.
Know how you can contact your provider if you have