THURSDAY, June 23 (HealthDay News) -- Cocaine contaminated with levamisole, a cheap and widely available drug used to deworm livestock, could result in a U.S. public health epidemic, experts warn.

In a report released online in advance of publication in an upcoming print issue of the Journal of the American Academy of Dermatology, doctors revealed that patients in Los Angeles and New York who smoked or snorted cocaine diluted or "cut" with the veterinary drug developed serious skin reactions.

Six patients developed patches of purple necrotic skin on their ears, nose and cheeks, as well as other parts of their body, the doctors reported. In some instances, the cocaine users suffered permanent scarring as a result of using the tainted drug.

Two similar cases were also reported in San Francisco along with others that reported additional side effects, including agranulocytosis -- a potentially life-threatening immune-system disorder.

The problem, however, could reach epidemic proportions. The U.S. Department of Justice has reported that up to 70 percent of cocaine in the United States is contaminated with levamisole. Once prescribed for humans, the drug was discontinued after patients who took the drug developed conditions similar to the cocaine users.

"We believe these cases of skin reactions and illnesses linked to contaminated cocaine are just the tip of the iceberg in a looming public health problem posed by levamisole," lead researcher Dr. Noah Craft, of the Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, said in an institute news release.

Initially baffled by the severity of the skin damage, Craft added that the report was published to increase awareness about these skin reactions, which could be misdiagnosed as vasculitis (a rare blood vessel autoimmune disorder), and to educate both the public and health professionals about the additional risks associated with cocaine use.

More information

The U.S. National Library of Medicine provides more information on cocaine.