Pityriasis Rosea - Topic Overview
How is pityriasis rosea diagnosed?
will diagnose pityriasis rosea by looking at the rash. Diagnosis can be
hard when only the herald patch is visible, because the condition is often
mistaken for ringworm or eczema at this time. After the rash appears, diagnosis
is generally clear.
If the diagnosis is unclear, your doctor may
potassium hydroxide (KOH) test to make sure the rash
is not caused by a
fungal infection. A skin sample may be taken from the
infected area and examined under the microscope (biopsy). If the
diagnosis is unclear in a sexually active person, a test for syphilis is often
How is it treated?
Pityriasis rosea goes away without treatment. It usually lasts about 6 to 8 weeks. If the rash itches, you may wish to use skin lotions and lubricants to soothe itching. If symptoms are severe, your doctor may prescribe anti-inflammatory medicines such as corticosteroids to relieve itching and reduce the rash.
Although treatment isn't needed, antiviral medicines like acyclovir may shorten the time you have the rash, especially if you take them when the rash first starts.
the rash to sunlight may make it go away more quickly. But exposing your skin
to the sun too long can result in sunburn and increase your risk of
If the rash lasts more than
3 months, contact your doctor.
To relieve itching at home:
- Try to stay cool. Getting too warm and sweaty can make the rash and itching worse.
- Avoid taking hot showers or baths. Keep the water as cool as
you can tolerate.
- Try an oatmeal bath, such as Aveeno Colloidal
Oatmeal bath, to help relieve itching. You may also wrap
1 cup of oatmeal in a cotton cloth and boil as
you would to cook oatmeal. Use this as a sponge and bathe in cool water without
- Try an
over-the-counter 1% hydrocortisone cream for small
itchy areas. Use the cream very sparingly on the face or genitals.
Note: Do not use the cream on children younger than age
2 unless your doctor tells you to. Do not use in the rectal or vaginal area in
children younger than age 12 unless your doctor tells you to.
antihistamine, such as chlorpheniramine maleate
(Chlor-Trimeton) or diphenhydramine (Benadryl). Don't give antihistamines to
your child unless you've checked with the doctor first.
- Apply a moisturizer or calamine
lotion to the skin while it is damp.
- Use as
little soap as possible. Use gentle soaps, such as Basis, Cetaphil, or Dove. Avoid deodorant soaps when you have a rash.