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Pityriasis rosea: Who gets and causes

Researching the disease

Through research, dermatologists are gaining a better understanding of why people develop pityriasis rosea.

researcher in a lab

What causes pityriasis rosea?

Why some people get this disease is still a bit of a mystery. It’s likely caused by a virus. Dermatologists have found human herpesviruses in the rash, blood, and saliva of people who have pityriasis rosea.

How can herpesviruses cause pityriasis rosea?

These are many types of human herpesviruses. The ones found in people with pityriasis rosea are human herpesviruses 6 and 7. These types cannot cause cold sores or genital herpes.

Human herpesviruses 6 and 7 are common. Many Americans become infected with them at an early age. Children often get infected when someone sneezes or kisses them. Once you get these viruses, they remain inside the body.

These viruses generally don’t cause a problem because your immune system keeps them under control. It’s possible that people get pityriasis rosea when their immune system lets down its guard, which allows the viruses to travel around the body and reproduce.

Whether this happens has yet to be proven. It’s also possible that people get pityriasis rosea when they first catch these viruses.

More research is needed to find out what’s happening.

While what causes pityriasis rosea is still a bit of a mystery, knowing how to diagnose it is straightforward. Find out how a board-certified dermatologist diagnoses this disease at, Pityriasis rosea: Diagnosis and treatment.

Getty Images

Drago F, Broccolo F, et al. “Pityriasis rosea: An update with a critical appraisal of its possible herpesviral etiology.” J Am Acad Dermatol 2009;61:303-18.

Julapali M, Travers JB. “Papulosquamous skin eruptions.” In: Fitzpatrick JE, et al. Dermatology Secrets Plus (5th edition). Elsevier. China, 2016:67-8.

Wood GS, Reizner GT. “Other papulosquamous disorders.” In: Bolognia JL, et al. Dermatology. (fourth edition). Mosby Elsevier, China, 2018:170-2.