Mexican public health officials in the northern state of Sonora have confirmed the first case of krokodil in the city of Nogales, which borders Arizona.
In January, Leticia Amparano Gamez, the state's director of mental health, said that an adult male who sought medical attention at a public clinic came in with skin lesions associated with intravenous use of krokodil, Mexican magazine Proceso reported.
Krokodil, which was first used in Russia, is made by cooking crushed codeine pills with household chemicals like paint thinner. The homemade drug contains impurities that damage the user's circulatory system, leaving scaly green scabs and causing flesh to rot off the bone.
Some experts believe the widely-reported spread of krokodil in the United States is overstated. They claim that injuries associated with the drug are actually caused by dirty needles.
Gamez said that the patient in question also used crystal meth, cocaine and heroin, according to Mexican news website Aristegui Noticias.
In an interview with Proceso last December, Jacobo Fox Inzunza, director of the Center for Youth Integration in Sonora, said that border cities like Nogales were at "highest risk" for krokodil because the high incidence of intravenous drug use there.
"Last year, young people in the border states of the United States began using synthetic marijuana and bath salts, and in a few months we began to see teens in Mexican states and municipalities using them," Inzuna told the magazine. He said the same thing could happen with krokodil.
In November, a 17-year-old was treated in Puerto Vallarta after she claimed to have injected krokodil into her genitals. In January, Mexican health officials said that the girl was a Houston, Texas, resident who had sought medical attention while visiting relatives in Mexico.
Although numerous cases of krokodil use in the United States have been reported since September 2013, apart from two cases in 2004, the Drug Enforcement Administration has yet to confirm the presence of desomorphine in the United States.
According to experts, part of the reason why the drug hasn't taken hold in the U.S. is because it's harder to get codeine than it is to buy cheap heroin.
"Relatively accessible and inexpensive alternatives, such as heroin, make krokodil production and use in the United States highly unlikely," Dr. Michael Lynch, medical director of the Pittsburgh Poison Center, told The Huffington Post in December.
Heroin use has its own perils, and it's become even more deadly of late, as evidenced by fentanyl-spiked batches that have been linked to the overdose deaths of more than 50 people since September.