Officials said the cream contained methylmercury, a very toxic type of mercury. (Representational)

A Sacramento, California, woman went to the emergency room with numbness in her hands and feet, slurred speech and trouble walking in July. The 47-year-old mother of five wasn't having a stroke or a heart attack. She was suffering from mercury poisoning from a tainted anti-wrinkle cream imported from Mexico, KCRA reported.

She's been in the hospital since then, according to her son, who told KCRA he wished to remain unidentified. His mother, who hasn't been identified, was initially able to respond to verbal commands before she entered her semi-comatose state.

Olivia Kasirye, the public health officer for the Sacramento County Department of Health Services, told CBS Sacramento that the woman's cream contained methylmercury, a very toxic type of mercury. This is the first time a methylmercury poisoning from face cream has occurred in the United States, the department said in a statement.

Kasirye is urging the public to immediately discontinue use of similar skin creams imported from Mexico because of how dangerous methylmercury is for adults and children.

"We don't know whether this was an intentional change, or whether there was a mistake in the person who was adding the mercury," she said, telling the station that the there's an informal network of suppliers who bring the altered skin creams into the country.

The most common way that people are exposed to methylmercury is through eating fish and shellfish that contain the toxin, according to the Environmental Protection Agency.

Skin exposure to methylmercury can affect the central and peripheral systems, with symptoms ranging from tremors, memory loss and cognitive and motor dysfunction, according to the World Health Organization.

The average amount of mercury in blood is about 5 micrograms per liter because of the amount of mercury that is likely to be in someone's diet, according to the New York State Department of Health. The woman had 2,630 micrograms per liter in her blood, according to KCRA.

"It can reach high levels in the blood and it can also cross over into the brain," Kasirye told the station. "Once it crosses into the brain, even if you go to the hospital, the medication we have cannot pull it out."

WHO and the Pan American Health Organization reported in 2017 that mercury was used in skin-lightening products for its ability to suppress melanin, resulting in fading hyperpigmentation, acne scars and overall skin tone. The FDA stated in 2016 that mercury-containing products were also sold as anti-wrinkle creams, and warned that cosmetic exposure could cause mercury vapor inhalation and mercury contamination through skin-to-skin contact. The agency also cautioned against skin-care products manufactured abroad that are then sold, often illegally, in places that cater to Latino, Asian, African and Middle Eastern communities.

The woman's son told CBS Sacramento that his mother knowingly used the altered product from Mexico twice a day for years because it worked better than the creams sold in drugstores. The woman purchased the cream from someone she knew, according to CBS Sacramento.

Sacramento County Public Health and the California Department of Public Health will test similar creams in the Sacramento area for methylmercury.

There have been more than 60 poisonings linked to foreign-branded, unlabeled or homemade skin creams tainted with a less-toxic form of mercury, according to a Sacramento County Department of Health Services statement. The Sacramento County Department of Health Services published a list of products that have tested positive for mercury on its website.

Kasirye told KCRA that her department wants people to be careful about the products they purchase, especially if they're not purchased from a drugstore.

In November, 51 environmental and public health groups requested that Amazon and eBay get rid of illegal skin-care products containing high levels of mercury.

In June, a judge in Alameda County Superior Court ruled that a corporate social responsibility advocacy group couldn't sue Amazon for selling skin-whitening creams that contain very high level of mercury without the cancer warning labels usually required by law, according to the Mercury News. The judge agreed that Amazon wasn't responsible for warning labels on products listed by vendors. A court in Pennsylvania agreed with the ruling weeks later but held that Amazon could be held accountable for harmful effects of flawed products. (The Washington Post is owned by Amazon founder and chief executive Jeff Bezos)

There's no prognosis for the woman's condition, according to CBS Sacramento.

"It was a huge slap in the face honestly," the woman's son told the station. "You don't really expect something this severe to happen with just a face lotion."