Researchers at the Stanford University School of Medicine, in collaboration with the genetics company 23andMe, have identified a genetic basis for rosacea, an incurable and poorly understood skin disease.

Treatment options for rosacea now are limited, but finding out what causes the disease could help scientists identify new targets for treatment and understand its links to other known diseases.

A paper describing the study’s findings was published online today in the Journal of Investigative Dermatology.

Rosacea causes skin on the face to redden and can result in acnelike bumps. “Rosacea is a very visible, inflammatory disease of the skin,” said Anne Lynn Chang, MD, lead author of the paper and an assistant professor of dermatology at Stanford. “It can lead to permanent scarring.”

According to the National Rosacea Society, the disease affects around 14 million Americans, or 5 percent of the population. In northern European countries, the prevalence is greater, at around 10 percent of the population. Rosacea is most visible in fair-skinned people but affects people of all skin types.

“It is one of the most common things we see in dermatology clinics that is incurable and not easily treatable,” Chang said.

Rosacea patients can also experience itching, stinging and burning sensations on the affected skin; these feelings, accompanied by the visible skin changes rosacea causes, can make sleeping, concentration and social interactions difficult. Other research suggests the disease could be associated with underlying systemic diseases that affect other organ systems in addition to the skin.