Use of unlicensed black salve for cutaneous malignancy

To the Editor: The most frequently diagnosed cancers in Australia are non-melanoma skin cancers.1 Recommended treatments include surgical excision, radiotherapy and topical chemotherapy for in-situ lesions.2 There has been an increase in sales of lotions and salves that claim to eradicate skin lesions and promote removal of skin cancers. In 2012, the Therapeutic Goods Administration issued a public warning strongly advising patients against the use of red and black salves.3 We report a recent case illustrating the complications resulting from use of these unlicensed products.

A 55-year-old man presented to the emergency department at Princess Alexandra Hospital, Brisbane, with a tissue defect on his right temple (Box). The patient had applied black salve to a lesion, which he believed to be cancerous, over the previous 4 months.

Before the Therapeutic Goods Administration warning, topical preparations such as black and red salves were being sold online to Australians as an alternative treatment for skin cancer. These products contain sanguinarine, a benzylisoquinolone alkaloid derived from bloodroot (Sanguinaria canadensis).3 This compound is hypothesised to induce tissue necrosis by blocking the sodium–potassium pump, inhibiting nuclear factor-κB or impeding cell cycle progression.4

Zinc chloride has also been identified in salve preparations. Sanguinarine and zinc chloride may cause significant tissue necrosis of both cancerous and healthy tissue, leading to significant scarring and disfigurement.5 In the absence of a biopsy, some patients may commence alternative treatment before attaining a diagnosis of skin cancer, and a very real risk of recurrence and metastasis remains.4 As a consequence, there may be delays in diagnosis, and it may be difficult to identify the primary site of malignancy.

It is imperative for health professionals to recognise that these unlicensed products may lead to adverse outcomes, and for consumers to realise that alternative therapies that have been described as natural are not necessarily safe or, by any standard, risk-free.

Tissue defect on the patient’s right temple following use of black salve