The next time a patient presents with a possible case of recalcitrant scabies, look carefully and ask questions.
What you may think is scabies actually may be a manifestation of addiction to methamphetamine, according to Dr. Kathleen Hectorne, a physician at the Mayo Clinic in Rochester, Minn.
It's treated, “and it's not getting better, because it's a [consequence] of meth use where they're picking at their skin,” she said, adding that this disorder is also known as “meth mites.” These same patients also may suffer from anorexia or weight loss.
Another sign of possible methamphetamine use is delusions of parasitosis, in which patients feel like insects are crawling on their skin, although Dr. Hectorne noted that “not all cases feel like bugs. Some people say they think the drug is coming out of their skin.”
To remove the imaginary bugs or other items they think are in their skin, meth users may use safety pins, needles, or other sharp objects, said Dr. Matthew A. Torrington, an addiction medicine physician in Los Angeles. “Patients will tell you they feel like there is something in their skin, and they will [pick at it] to the point that they tear their flesh open,” he said.
These irritations then become infected secondarily, said Dr. Sullivan Smith, an emergency physician in Cookeville, Tenn. “You name it: They will get staph, strep, and all kinds of enterics,” he said. “It's a polymicrobial kind of infection.” Although the infections often can be treated with antibiotics, most of them would go away entirely if the patients stopped scratching.
Patients addicted to methamphetamine have the “typical IV drug users' skin infections and abscesses,” he said. “There are a couple of reasons for that. One is a microbial issue, because they don't use sterile techniques and they share needles. But additionally, meth is not a clean drug—this stuff is made with battery acid, and that causes skin abscesses, too,” said Dr. Smith, who also works as a police officer and has been involved in raids on meth labs.
In addition, the byproducts produced by the meth manufacturing process can be irritating to the skin and cause lesions that look like a rash. No one has done much research on these byproducts because “we've never really focused on what else is in it. We're always just focused on how much meth is there,” Dr. Smith noted.
To treat these patients, physicians first need to establish that they are drug addicts, which can be tricky, Dr. Hectorne said. “It always helps to see if they test positive for the drug, but you need their permission to do that,” she said.
Dr. Torrington agreed. “You're going to have to be able to get the patient's history, and if the patient denies [using meth], it's going to be hard.” There are specific tests that can be done for methamphetamine but the drug is metabolized very quickly by the body, so it might disappear before it can be found. There is also a urine test for amphetamine and methamphetamine, “but they have more cross reactivity with other substances than any other drugs of abuse,” he added.
Dr. Hectorne became interested in the dermatologic manifestations of methamphetamine abuse after a police officer came to the clinic to give a talk on the subject: “I thought, 'This is something we're probably seeing and not picking up on totally.'”
Once the problem has been detected, the only way to cure the dermatologic manifestations is to stop the abuse, Dr. Torrington said. “In most cases, the symptoms will resolve when the meth is removed. It can take a few days or weeks,” although in some addicts the symptoms can persist for months or years afterwards, he said.
Dr. Torrington is an investor in and consultant to Hythiam Inc., a Los Angeles company that is developing a medical treatment called Prometa for methamphetamine addiction.
Although he declined to reveal the treatment's contents, the firm's patent application indicates that Prometa includes intravenous administration of flumazenil or another selective chloride channel modulator, combined with varying doses of other drugs as well as nutritional and vitamin supplements.
Results of a 45-patient open-label trial of the treatment regimen are expected in the first quarter of 2006, Dr. Torrington said.