The case of a Houston teen hospitalized in Mexico is shedding light on a new street drug known as "Krokodil" or "poor man's heroin.”

This flesh-eating "zombie" drug was all the rage in Russia, but appears to have arrived in the U.S.

Dr. Jeff Kalina at Houston Methodist Hospital says users mix painkillers with household products to separate and intensify the drug.

“They're taking codeine and breaking it down with solvents like gasoline to separate the narcotic from the rest of the medication,” he tells KTRH News.

One dangerous side effect -- it eats away at your flesh when injected.

“It gives a greenish, scaly skin that looks like a crocodile,” says Kalina.  “They're probably not getting all the solvent out of the mixture at the end, and when they inject the drug they're getting local tissue death, we call it necrosis or gangrene.”

Those symptoms have reportedly popped up near Chicago, in Arizona and Oklahoma.