A California woman sued the makeup retailer after sampling a new lip color. Can you really catch herpes that way?

A woman says she left Sephora in October 2015 with something she definitely didn’t go to the makeup giant to pick up: herpes. The California customer is now suing the retailer, claiming she contracted the "incurable lifelong affliction" after sampling a “common use” lipstick tube on display, TMZ reports.

There are limited details on the case, but TMZ reports that health-care professionals have confirmed the woman was diagnosed with herpes. Oral herpes is an infection usually caused by the herpes simplex virus 1, or HSV-1. It results in painful blisters around the mouth commonly known as cold sores or fever blisters. HSV-1 and a related infection, herpes simplex virus 2 (HSV-2), can also cause genital herpes, a sexually transmitted disease characterized by similar lesions on or around the genitals.

Herpes is spread through contact with someone with the infection, even if that person doesn’t have visible cold sores or genital lesions, says Pritish K. Tosh, MD, a Mayo Clinic infectious disease physician and researcher. In fact, many people carry the HSV-1 virus for herpes—nearly 70% of people worldwide—but most don’t have symptoms, says Dr. Tosh.

That makes it tough to know exactly how a person with the condition became infected. “Most people are acquiring herpes from people who have no knowledge that they have the infection," he says. Those symptom-free carriers make it "difficult to pinpoint how somebody actually acquired the infection,” he explains. Herpes spreads most easily when someone has a visible cold sore via skin-to-skin contact, like a kiss.

But what about contracting oral herpes from objects? Sharing lipstick—or other items that touch the lips, gums, and mouth, like utensils or water bottles—can also spread the infection. Someone with a cold sore shouldn’t share these or other items “until those lesions have crusted over and gone away,” says Dr. Tosh, at which point the possibility of transmission is lower.

Still, even if a person doesn’t have herpes symptoms, it’s still possible to spread small amounts of the virus on shared objects, enough to infect someone who has not been infected before, Dr. Tosh says. That means unsuspecting makeup testers need to be vigilant about taking hygiene precautions, he says. Consider sampling lipstick on a tissue or cotton swab instead of on your skin. And don't test a product on the back of your hand, either. If herpes viral particles are on the makeup product, you could transmit them to your hand, then inadvertently touch your mouth and become infected that way.

While it's possible that the woman suing Sephora did contract the virus from a product sample, Sephora had this to say in a statement to Bustle: "While it is our policy not to comment on litigation, the health and safety of our clients is our foremost priority. We take product hygiene very seriously and we are dedicated to following best practices in our stores."

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We don’t know what kind of herpes symptoms the woman in the lawsuit is living with, but typical herpes symptoms include cold sores or fever blisters, which can be painful and filled with fluid, according to the American Academy of Dermatology (AAD). Often, herpes sores break open, ooze, then crust over before going away entirely, only to return again and again. Some people might experience burning, itching, or tingling sensations on their skin before the lesions appear.

Talk to a doctor if you think you could have oral herpes. He or she can usually diagnose you by looking at your sores, but blood tests can detect the virus if you don’t have any visible symptoms. Antiviral creams and ointments can help limit some of the discomfort of oral herpes, and prescription pills might help shorten an outbreak, according to the AAD.