Contaminated cocaine use can cause painful, necrotic skin purpura
MedWire News: Using cocaine contaminated with the animal de-worming drug levamisole can result in painful, necrotic purple skin lesions and low levels of white blood cells, report US researchers.
"We've seen a lot of cases in Rochester alone, so it is important to alert the gatekeepers of medicine, the primary care physicians who are in the trenches every day, of this diagnosis," said study author Mary Gail Mercurio from the University of Rochester in New York.
"This is one of those entities that with familiarity and recognition, can go a long way in helping physicians to quickly make a diagnosis and intervene without embarking on an elaborate workup where nothing will pan out," she said.
Co-author Noah Craft (University of California, Los Angeles) and colleagues describe a series of six patients with remarkably similar dermatological symptoms after cocaine use, treated in clinics in New York and California over the past few months.
Symptoms included net-like purple skin discoloration or purpura on the body, which included painful eruptions, skin necrosis, and scabbing, all occurring after cocaine use.
In addition, all the patients had positive perinuclear antineutrophil cytoplasmic antibody values, a common feature of many autoimmune conditions. Three also had a low white blood cell count (neutropenia), which can significantly increase infection risk.
The study authors believe that the cause of these symptoms is contamination of the cocaine with levamisole, rather than cocaine use per se, as the symptoms of purpura and neutropenia have been observed before in connection with levamisole-contaminated cocaine use.
Craft et al explain that levamisole-contaminated cocaine has been in use in the USA since 2003, and resulting toxic reactions have increased dramatically since 2008.
"When we first started seeing these patients they all had a similar clinical picture, but they were really an enigma because they weren't falling into any other pattern we'd seen before. When a colleague at the National Institutes of Health mentioned levamisole contamination, we did toxicity screens and lo-and-behold, all the patients came up positive for cocaine," said Mercurio.
She concluded: "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."
The results of this study are published in the Journal of the American Academy of Dermatology.
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By Helen Albert