The Associated Press reports that the girl traveled to Mexico to visit relatives in November and checked into a local clinic soon after. She told doctors that she used the drug in Houston.
The story was first reported in early December, and health authorities recently confirmed that it's a probable case of Krokodil. The girl's current condition is unknown because she never returned to the health clinic for treatment after her initial visit.
Doctors believe the girl injected the drug into her genitals, where the skin lesions were found, according to British newspaper The Independent, which cited a Mexican newspaper. She said she had been taking the drug for two months.
Krokodil likely originated in Russia. Those who take the drug often experience green, scaly skin at the site of injection and gangrene, necessitating amputations.
The drug is very dangerous - those who get hooked on it usually die about two years after they first take the drug.
Experts believe the drug spread in Russia because heroin supply is limited and this drug acts as a substitute that users can make at home with codeine, gasoline, paint thinner, iodine, hydrochloric acid, and red phosphorous.
Some say the drug is now spreading in the U.S., but those claims are likely overblown. There have been very few cases confirmed in the U.S. so far.