Pityriasis Rosea (Medallion Disease): Symptoms, Course, and Treatment

What is pityriasis rosea?

Pityriasis rosea is an inflammatory skin rash that usually resolves spontaneously, primarily affecting the trunk and upper extremities. It most commonly occurs during adolescence and young adulthood, but can appear at any age. The disease resolves in most people within about 6–8 weeks.

What is the symbol of a medallion?

In many patients, a single, larger lesion may develop first. This initial lesion is called a herald patch or, colloquially, a "medallion." It is usually an oval, slightly pinkish-red or brownish plaque with fine scaling around it.

What does the rash look like?

Small oval lesions may be located parallel to the skin lines along the trunk. The distribution on the dorsal side is sometimes described as a "Christmas tree appearance". The appearance may vary depending on skin color, and temporary discoloration may persist after healing.

Will it itch?

It is possible, but not everyone experiences it. In some patients it may be mild, while in others it may be pronounced enough to affect daily life or sleep.

What causes pityriasis rosea?

The exact cause is not entirely clear. Some studies suggest a possible association with human herpesviruses 6 and 7 (HHV-6 and HHV-7); however, the disease cannot simply be described as a "herpes infection".

Is pityriasis rosea contagious?

It is generally accepted that the disease is not significantly contagious from person to person. Close contacts do not require routine treatment.

Is pityriasis rosea a sexually transmitted disease?

No. However, other diseases that cause a widespread rash on the trunk can resemble pityriasis rosea. If there is clinical suspicion, sexually transmitted infections should also be considered in the differential diagnosis.

How is pityriasis rosea diagnosed?

In classic cases, diagnosis is usually made through dermatological examination. If it is not typical, blood tests, fungal examination, or rarely a skin biopsy may be necessary.

Which diseases can it be confused with?

Tinea corporis

Guttate psoriasis

Some types of eczema

Drug rashes

Secondary syphilis

Can medications cause a similar rash?

Yes. Some medications can cause pityriasis rosea-like rashes. Newly started medications should be questioned during the evaluation.

How is pityriasis rosea treated?

Most patients do not require specific treatment because the rash resolves spontaneously. If necessary, moisturizers, appropriate topical corticosteroids, antihistamines, and phototherapy in selected severe cases may be considered.

Will there be any scarring after the rash disappears?

Permanent scarring is not expected; however, temporary darkening or lightening may occur, especially in people with darker skin tones.

Is pityriasis rosea important during pregnancy?

Pityriasis rosea occurring during pregnancy should also be evaluated. Studies regarding potential risks, particularly in early pregnancy, are not entirely consistent; a joint dermatology and obstetrics evaluation is necessary.

When should you consult a dermatologist?

If the diagnosis is uncertain

If the rash is very widespread

If itching affects daily life or sleep

If the rash lasts longer than two or three months

If there are unusual lesions on the palms or soles of the feet

If accompanied by fever or systemic symptoms

If it started after using the new medication

If there is pregnancy

Frequently Asked Questions

Is pityriasis rosea a fungal disease? No.

Is medallion disease contagious? It is generally not considered contagious.

Repetition? Possible, but not frequent.

How long does the rash last? About 6–8 weeks for most patients.

Dermatologist's Note

Pityriasis rosea is often a disease that resolves spontaneously. Clinically, it is important not to assume every widespread, scaly rash is pityriasis rosea. Dermatological examination is crucial when differential diagnosis is needed to rule out fungal infections, psoriasis, drug reactions, and other infections.