Bridget E. McIlwee, DO
Warning: graphic photographs below.
With recent advances in medicine, cure rates for the most common types of skin cancer can exceed 95%.1-4 Despite this, today many patients still resort to the use of ‘alternative skin cancer treatments’. Patients may be attracted to such treatments for their purported natural origins. However, it is imperative to realize that “natural” does not mean safe. Most of these so-called ‘natural’ treatments have never been shown to provide any clinical benefit; few, if any, of them are backed by scientific evidence. Furthermore, they can cause significant harm; some of their side effects may even be life-threatening.
One of the most popular of these ‘alternative skin cancer treatments’ is black salve, also called black ointment. It is sold under several brand names. It is most commonly used by patients who live in rural areas, where it is typically obtained from or recommended by ‘backwoods healers’. It can also be purchased on the internet and thus is quite widely available. One of the active ingredients of black salve is bloodroot, or sanguinaria (Sanguinaria canadensis, figure 1). This flowering perennial plant is native to the eastern United States, from Canada to Florida, and its habitat extends as far west as the Mississippi River.5,6
Black salve gets its name from the thick, black crust – or eschar – that it leaves on a patient’s skin after use. This black crust is the result of tissue death. The active components of black salve are zinc chloride and sanguinarine (the extract of the sanguinaria plant), both of which are escharotics – i.e., compounds that cause necrosis of living tissue.
The plant extract sanguinarine is a benzylisoquinoline alkaloid. It induces oxidative DNA damage, resulting in the death (apoptosis) of human tissue. The concentration of sanguinarine contained in typical OTC preparations of black salve kills all cells, whether they are healthy or diseased.7 This stands in stark contrast to evidence-based medical treatments, which preferentially destroy malignant tissue and leave healthy skin intact.
The destruction caused by black salve can result in massive scarring and disfigurement. In the worst cases, scarring is severe enough to cause loss of the body part treated. In one report, black salve ate away the entirety of a patient’s nose after he attempted to use it to treat a skin cancer.6 In another case, a patient’s repeatedly used black salve on abdominal skin nodules, eventually resulting in the development of holes connecting his outer abdominal wall to his intestines (enterocutaneous fistulas).
The use of black salve has never been shown to cure skin cancer. In fact, even if lesions appear to resolve after treatment with black salve, malignant cells may remain in the skin. This is incredibly dangerous, as the hidden cancer could grow and spread – or metastasize – to other areas of the body. The problem may only become apparent to the patient much later, when they are diagnosed with metastatic cancer.9 Some of these metastatic skin cancers can be fatal.
Furthermore, if a patient consults a physician after using black salve, the eschar and scarring can obscure the skin lesion. This makes it difficult or impossible to evaluate for the presence of cancer cells. Without a clear diagnosis of the lesion, the physician cannot prescribe an appropriate future course of treatment.
In peer-reviewed studies, black salve has never been shown to be an effective treatment for skin cancer. If patients utilize black salve, they run the risk of permanent scarring, disfigurement, and functional impairment. Most importantly, black salve may allow cancer cells to remain hidden in the skin; potentially later metastasizing to other areas of the body and threatening the patient’s life.
If you have a confirmed or suspected skin cancer, you should consult a board-certified dermatologist as soon as possible. He or she will discuss evidence-based options for treatment of your skin cancer, including the risks and benefits of each, and tailor a treatment plan to your individual situation. Depending on your diagnosis and specific needs, your dermatologist may recommend a single or a multi-course treatment for your skin cancer. Many skin cancers, if caught early and treated with evidence-based therapies, can be cured at rates approaching or greater than 95%.1-4
- Drake LA et al. Guidelines of Care for Basal Cell Carcinoma. J Am Acad Dermatol. 26: 1992; 117-120.
- Telfer NR et al. Guidelines for the management of basal cell carcinoma. Br J Dermatol. 141: 1999; 415-423.
- Alam M, Ratner D. Cutaneous squamous cell carcinoma. N Engl J Med. 344: 2001; 975-983.
- Tung R. Cleveland Clinic Center for Continuing Education: Nonmelanoma Skin Cancer. Available at: http://www.clevelandclinicmeded.com/medicalpubs/diseasemanagement/dermatology/nonmelanoma-skin-cancer/. Accessed 13 July 2016.
- Eastman KL, Mcfarland LV, Raugi GJ. A review of topical corrosive black salve. J Altern Complement Med. 2014;20(4):284-9.
- Eastman KL, Mcfarland LV, Raugi GJ. Buyer beware: a black salve caution. J Am Acad Dermatol. 2011;65(5):e154-5.
- Lee TK, Park C, Jeong SJ, et al. Sanguinarine Induces Apoptosis of Human Oral Squamous Cell Carcinoma KB Cells via Inactivation of the PI3K/Akt Signaling Pathway. Drug Dev Res. 2016.
- Cienki JJ, Zaret L. An Internet misadventure: bloodroot salve toxicity. J Altern Complement Med. 2010;16(10):1125-7.
- Sivyer GW, Rosendahl C. Application of black salve to a thin melanoma that subsequently progressed to metastatic melanoma: a case study. Dermatology Practical & Conceptual. 2014;4(3):77-80. doi:10.5826/dpc.0403a16.
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