Pityriasis Rosea
A harmless rash that usually starts with one larger, oval, scaly patch (the herald patch), followed a week or two later by many smaller pink or darker patches over the chest, back and upper arms. It clears on its own.
Quick answer: Pityriasis rosea is a common, harmless rash, most often in people aged 10 to 35. It usually starts with one larger scaly ‘herald patch’, then smaller oval patches spread over the trunk in a Christmas-tree pattern. It clears on its own, usually within 6 to 12 weeks. Moisturisers and mild steroid creams ease any itch.
How common. Common, especially from age 10 to 35, and a little more often in women. It tends to cluster in colder months and sometimes in families or schools.
Causes. Not fully known. It’s linked with reactivation of human herpesviruses 6 and 7 (relatives of the cold sore virus, not the same one). The chance of passing it on is very low. Some medicines can cause a similar rash.
Symptoms. Many people (not all) get a single 2–5 cm oval patch with a scaly edge first, usually on the trunk. Then crops of smaller oval patches appear, lined up along the skin creases of the back like the branches of a fir tree. The face, hands and feet are usually spared. About half of people itch. Some feel mildly unwell with a headache or temperature before it starts. On darker skin the patches can look grey, brown or purple.
Look-alikes. Ringworm (the herald patch is often mistaken for it), guttate psoriasis, discoid eczema, a drug rash, pityriasis versicolor and secondary syphilis, which can look very similar but usually affects the palms and soles.
How it’s diagnosed. From the look and story. If the picture isn’t typical, your GP may scrape the skin to check for fungus, or do a blood test for syphilis, particularly if the rash is on the palms or soles. A biopsy is rarely needed.
The pityriasis rosea ladder
It goes away by itself. Treatment is only for comfort, and most people need nothing at all.
- Step 1 · Self-careMoisturiser and a soap substituteFragrance-free moisturiser, lukewarm showers, and loose cotton clothes.
- Works
- Eases dryness and mild itch; doesn’t change how long the rash lasts
- Cost
- About $10–20
- How long
- Until it fades
- Watch for
- Hot showers, perfumed products and sweaty exercise can make the itch worse for a while.
The rash is leaving anyway. You’re just making the exit comfier.
- Step 2 · PharmacyHydrocortisone 1% cream and an antihistamineHydrocortisone twice a day on itchy patches; a sedating antihistamine at night if itch disturbs sleep.
- Works
- Helps itch; little trial evidence
- Cost
- About $8–15 each
- How long
- Days to a few weeks
- Watch for
- Sedating antihistamines cause next-day drowsiness. Check with a pharmacist for children or in pregnancy.
Calms the itch. Doesn’t hurry the rash.
- Step 3 · PrescriptionStronger steroid creamFor itch that hydrocortisone doesn’t touch.
- Works
- Itch relief; doesn’t speed clearing
- Cost
- About $15–30 a tube
- How long
- Up to 2 weeks at a time
- Watch for
- Avoid strong steroids on the face and skin folds.
Stronger cream, same rash timetable.
- Step 4 · PrescriptionAciclovir tabletsSometimes used early in a widespread or troublesome rash.
- Works
- A 2019 Cochrane review found high-dose aciclovir probably helps the rash clear faster, based on a few small trials
- Cost
- About $20–40
- How long
- 1 week
- Watch for
- Not routinely needed for a condition that clears on its own.
A shortcut for some, not a must for most.
- Step 5 · SpecialistLight therapy (UVB)For severe itch or a rash that lingers, through a dermatologist.
- Works
- Can ease itch; evidence on speeding clearing is unclear
- Cost
- Medicare rebates; travel and time add up
- How long
- Several sessions a week for a few weeks
- Watch for
- May leave darker patches for a while, especially on darker skin.
Rarely needed. Most rashes have packed up long before the booking.
Save your money
Popular, heavily marketed or often asked about, but the evidence is weak or says no.
- Antifungal creamsIt isn’t a fungal infection, so they won’t help, unless a scraping shows ringworm.
- Keeping children homeThe chance of spreading it is very low, so school, childcare and work are fine.
What you can do
- Moisturise daily and use a soap substitute.
- Choose lukewarm showers and loose cotton clothing.
- Use hydrocortisone or an antihistamine at night if itch is a problem.
- Take a photo of the herald patch: it helps your GP if the diagnosis isn’t clear.
- Give it time. New patches can keep appearing for the first few weeks; that’s normal.
See your GP if
- You’re pregnant (see your GP or maternity team promptly)
- You’re not sure it’s pityriasis rosea, or it’s on your palms, soles or face
- The itch is severe
- It hasn’t cleared after 3 months
- You feel unwell, or you have mouth or genital sores
Pregnant? Small studies have linked pityriasis rosea in the first 15 weeks of pregnancy with a higher chance of miscarriage, though the overall risk is low. Contact your GP or maternity team promptly about any new rash in pregnancy.
Outlook. The rash usually fades in 6 to 12 weeks, occasionally up to 5 months, and heals without scars. Colour changes on darker skin can take a few months to even out. Only about 2 to 3 in 100 people get it again.
Common questions
Is pityriasis rosea contagious?
The chance of passing it on is very low. Children don’t need to stay home from school or childcare, and adults can keep working.
How long does pityriasis rosea last?
Usually 6 to 12 weeks from the herald patch, occasionally up to 5 months. New patches can keep appearing for the first few weeks. It clears without scarring.
What triggers pityriasis rosea?
It’s linked with reactivation of herpesviruses 6 and 7, which most people catch in childhood. Stress or illness may play a part. Some medicines cause a lookalike rash.
What does the herald patch look like?
A single oval or round patch, about 2 to 5 cm, pink or darker than your skin with a fine scaly edge, usually on the chest, back or tummy. It appears days to 2 weeks before the wider rash, and it’s often mistaken for ringworm.
Is pityriasis rosea dangerous in pregnancy?
Small studies link it with a higher chance of miscarriage when it starts in the first 15 weeks, though the overall risk is low. See your GP or maternity team promptly.
Does sunlight help pityriasis rosea?
Some people find gentle sun eases the itch, and light therapy is used for severe cases. Avoid sunburn, which irritates the skin.
Can pityriasis rosea come back?
Rarely. Only about 2 to 3 in 100 people get it a second time.
Evidence and more information
- British Association of Dermatologists: Pityriasis rosea patient leaflet (2023)
- NICE CKS: Pityriasis rosea
- Contreras-Ruiz et al, Cochrane 2019: Interventions for pityriasis rosea
- NHS: Pityriasis rosea
maladywise.com/pityriasis-rosea/