Black Drawing Salve For Boils

When it comes to curing skin ailments — from removing a splinter to treating cancerous growths — some folks prefer do-it-yourself methods to doctors. For many, the tool of choice is drawing salve.

While some people cook up their own concoctions, most turn to the plethora of products on drug store shelves. Judging by the number of Google hits — close to 600,000 — these products have quite a following.

What is drawing salve?

At face value, salve can act as a strong moisturizer for dry skin, yet some believe it has "drawing" properties to help draw foreign objects from the skin like splinters.

Dermatologists say there's no evidence for that "drawing" application in humans. One reason there's not much evidence on what the salves can do is that they're basically just a folk remedy, said Dr. Alan S. Boyd, a professor of dermatology at Vanderbilt University in Nashville. But some folks may be taking their cues from veterinarians. Products like ichthammol have long been a go-to preparation for vets treating abscesses on the bottom of horses' feet. The advice to clients with a foot sore horse is almost always to slather on the ichthammol.

Ichthammol, for example, traces back to the 19th century, explained Boyd who wrote a review article on the topic for the International Journal of Dermatology in 2010. Ichthammol itself is made of sulfonated shale oil. And while there hasn't been much written about it, there are historical accounts of sulfonated shale oil being used to aid in wound healing that go back as far the 1400s, Boyd said. Then in the late 1800s, a dermatologist wrote about the salve, recommending its use in the treatment of eczema.

And while it may indeed help with eczema, there's "much better stuff being used today," Boyd said. Moreover, Boyd noted he's yet been able to find any double blind placebo controlled trials — the gold standard in medicine — testing ichthammol's efficacy. The good news, he added, is that the product doesn't seem to have any significant side effects.

What is black drawing salve?

Like many home remedies, salves are mostly benign — the exception being the use of "black salve" for treating skin cancer. At best they may leave a big scar, experts say. At worst, they've been known to result in death.

Black salves "are made from completely different chemicals," than ordinary salves, Boyd said. "They kill skin cells indiscriminately."

So while a black salve can indeed obliterate cancerous lesions that aren't life-threatening, "so will a blow torch," Boyd said, adding that he's seen people "with big divots in their skin the size of a nickel to a silver dollar."

Black salve is definitely bad news for skin, said Dr. Shari Lipner, a dermatologist at NewYork-Presbyterian and Weill Cornell Medicine in New York City. "Patients are getting information off the internet that says it will cure skin cancers," Lipner said. "It has a host of ingredients, including zinc chloride and sanguinarine. These two together can really damage the skin."

The real danger is that the treatment will mask a deadly cancer, said Dr. Laura Ferris, an associate professor of dermatology at the University of Pittsburgh Medical Center. "There have been two cases reported where instead of getting traditional therapies, people used black salve to treat melanomas and died when the tumors metastasized," Ferris said. "The best case scenario with this is your low-risk tumor goes away leaving a big scar, the worst case is when you have a high-risk cancer and the tumor metastasizes and kills you."

The problem with treating a melanoma with a black salve is that it hits just the outer layer of the skin, while the cancer extends deeper and continues to grow and then spread, Lipner explained.

Ferris can't see the logic of treating even less dangerous skin cancers with black salve: "Maybe in 20% of cases the basal cell carcinoma went away, but people end up with a way worse scar than I would have given them in a 20-minute procedure with local anesthetic."

Linda Carroll is a Peabody Award-winning journalist who is a contributing health and medicine writer for NBC News and TODAY. She is co-author of three books: "The Concussion Crisis: Anatomy of a Silent Epidemic", "Out of the Clouds: The Unlikely Horseman and the Unwanted Colt Who Conquered the Sport of Kings" and "Duel for the Crown: Affirmed, Alydar, and Racing's Greatest Rivalry".