Realgar, a commonly used traditional Chinese medicine, has – according to the teachings of Traditional Chinese Medicine (TCM) – acrid, bitter, warm, and toxic characteristics and is affiliated with the Heart, Liver and Stomach meridians. It is used internally against intestinal parasites and treat sore throats, and is applied externally to treat swelling, abscesses, itching, rashes, and other skin disorders.
Chemically, it is nothing other than arsenic sulphide. Despite its very well-known toxicity, is thought by TCM-practitioners to be safe, and it has been used in TCM under the name ‘Xiong Huang’ for many centuries. TCM-practitioners advise that the typical internal dose of realgar is between 0.2 and 0.4 grams, decocted in water and taken up to two times per day. Some practitioners may recommend slightly higher doses (0.3-0.9 grams). Larger doses of realgar may be used if it is being applied topically.
Toxicologists from Taiwan report a case of fatal realgar poisoning after short-term use of a topical realgar-containing herbal medicine.
A 24-year-old man with atopic dermatitis had received 18 days of oral herbal medicine and realgar-containing herbal ointments over whole body from a TCM-practitioner. Seven days later, he started to develop loss of appetite, dizziness, abdominal discomfort, an itching rash and skin scaling. Subsequently he suffered generalized oedema, nausea, vomiting, decreased urine amount, diarrhoea, vesico-oedematous exanthemas, malodorous perspiration, fever, and shortness of breath.
He was taken to hospital on day 19 when the dyspnoea became worse. Toxic epidermal necrolysis complicated with soft tissue infection and sepsis were then diagnosed. The patient died shortly afterwards of septic shock and multiple organ failure. Post-mortem blood arsenic levels were elevated at 1225 μg/L. The analysis of the patient’s herbal remedies yielded a very high concentration of arsenic in three unlabelled realgar-containing ointments (45427, 5512, and 4229 ppm).
The authors of this report concluded that realgar-containing herbal remedy may cause severe cutaneous adverse reactions. The arsenic in realgar can be absorbed systemically from repeated application to non-intact skin and thus should not be extensively used on compromised skin.
The notion that a treatment that ‘has stood the test of time’ must be safe and effective is very wide-spread in alternative medicine. This, we often hear, applies particularly to the external use of traditional remedies – what can be wrong with putting a traditional Chinese herbal cream on the skin?? This case, like so many others, should teach us that this appeal to tradition is a classical and often dangerous fallacy. And the ‘realgar-story’ also suggests that, in TCM, the ‘learning-curve’ is very flat indeed.
Chinese and Ayurvedic remedies are often contaminated with toxic heavy metals. But the bigger danger seems to be that some of these traditional ‘medicines’ contain such toxins because, according to ‘traditional wisdom’, these constituents have curative powers. I think that, until we have compelling evidence that any of these treatments do more good than harm, we should avoid taking them.