Plasters, Pastes, Salves and Liniments:
The Many Faces of Chinese Herbal Medicine, Part 2
Chinese herbal medicine (CHM) is a vast science that has developed over no less than the last 3000 years. Part one of this article, Elixirs, Wines, Pills and Porridges (Qi Journal, Vol 19, No 1, Spring 2009), described the different forms of Chinese herbal medicine that are used for internal administration. Many diseases and other health conditions however need herbal medicines applied topically in addition to, or instead of, internally. In certain medical specialties, such as orthopedics and traumatology (Gu Shang Ke 骨伤科, or Die Da Ke 跌打科) or dermatology, the use of herbs externally on the body is sine qua non in practice. In the western world, where most acupuncture and Oriental medicine (AOM) providers have generalist training in internal medicine, there is scant use of herbs topically except for in limited cases where products are commercially available. In Asia the more extensive use of topical herbs is still alive and thriving, and even here in the western world there are pockets of highly skilled manufacturers of traditional topical herbal preparations and clinicians who understand their effective applications.
External Herbs in Early Medical History
Between 1972 and 1974 the tomb sites known as Ma Wang Dui (马王堆) were excavated and their contents examined. Ma Wang Dui is located in what is now as Changsha, Hunan Province, People’s Republic of China, and is the tomb site of Li Cang, Lord of Dai, who was interred in 186 BCE (Western Han Dynasty). Li, like many of the intelligentsia of his day, was an avid collector of books, or at least what would have been the equivalent of books in the Han dynasty. In Li’s time, writing (e.g. “books”) was done on thin flat strips of bamboo lashed together with silk cords that could be rolled up like scrolls. His tomb contained much of his collection, and archeologists excavated hemerological texts (texts on the study of calendars), writings about mathematics, and other books on diverse subjects such as military strategy, cartography, and music. Included were also some of the earliest known versions of the Yi Jing (I Ching) and the Dao De Jing (Tao Te Ching). Most significantly for the topic of this article, the Ma Wang Dui tombs also held a significant amount of medical texts, the oldest untouched examples of this literary genre as of yet unearthed in China.
The medical works found in Ma Wang Dui were diverse. There were charts of Dao Yin exercises, a book on fetal development and childbirth, manuals of disease treatment, and the earliest examples of the channels used today in Chinese medicine to name a few. Acupuncture was absent from these texts (acupuncture is a younger addition to the repertoire of Chinese medicine), but moxibustion and herbal medicine were amply represented. One of the manuscripts in particular, the manuscript entitled Prescriptions for Fifty Two Diseases, listed several types of heat therapy that included the topical use of herbs.
The first of these was called Roasting (Zhi 炙). In this technique various medicinal herbs would be applied topically to a part of the patient’s body and then that part would be help over a heat source to allow the herbs to penetrate. Next was Hot Pressing (Yun 熨). Different from Roasting, Hot Pressing used already heated herbs, most likely wrapped in a cloth of some type and then pressed against the painful or diseased part of a patient’s body. This technique, as will be described below, is still used in contemporary practice. The third method is Fumigation (Xun 熏), where smoke or steam made with various burning or boiling herbs would be allowed to wash over a patient’s body. One example of this type of treatment was a recipe calling for a patient to squat over the smoke from burning herbs to treat anal pinworms or hemorrhoids. The last method of external herbal therapy from this manuscript is Balneotherapy, the soaking of effected parts of the patient’s body in hot medicinal baths. For example, soaking in a bath made with peach leaves was indicated for the treatment of itching. Both of these last two treatment methods are also used to this day. And then now, this is where we go – to a look at the use of external herbal preparations in today’s clinical practice of Chinese medicine.
Poultices, plasters, creams, and some other preparations are known collectively as Gao (膏) in Chinese, and these are some of the most common modern forms of externally applied herbs. Poultices are usually made from dried herbs that are first ground into a fine powder. The powder is then mixed with some form of medium, usually oils (such as sesame), honey, water, tea, alcohol, or egg whites, and in modern times occasionally with petroleum jelly. The result of this mixing is a paste-like substance that is applied topically to effected areas of the body, covered with plastic or gauze, and left in place for a period of time.
Poultices are a favorite method of treatment for orthopedic conditions such as acute injuries or chronic pain conditions. External herbal treatment, often combined with acupuncture and the internal administration of Chinese herbs, usually leads to faster clinical outcomes. Poultices are especially useful in treating patients who either because of intolerance or herb-drug contraindications cannot take herbal formulas internally. Just as with internal herbal formulas, external poultices have to be applied according to differentiations of syndromes. For example, cooling formulas are used when the patient presents with heat signs and vice versa.
In addition to being used for traumatic injury, poultices are sometimes used to treat conditions of internal medicine. For example, in my clinic, women who have infertility due to scarring or partial obstruction of the fallopian tubes are given a poultice to place in their navel.
San Huang San – A Cooling Poultice 三黄散
Ingredients: Da Huang, Huang Qin, Huang Bai
Functions: Clears heat, dries damp, resolves toxins, disperses fire, stops pain and itching
San Huang San is a famous formula, although there are many variations of the formula ingredients in different source texts (i.e., another version of the formula contains Huang Bai, Huang Lian, Huang Qin and Zhi Zi). This formula in particular is used for swollen, hot and painful injuries (such as many acute traumas), although can be used for other hot swellings such as insect bites.
While still technically considered Gao (as are poultices), the term “plaster” in English usually refers to commercially prepared formulas that adhere to the body. Herbs are placed onto or impregnated in a backing, such as cloth, plastic or leather (for some, dog skin was traditionally used), and then made sticky with an adhesive. Medicated plasters often contain aromatic herbs such as borneol or camphor and thus have an immediate warming or cooling sensation on the skin. In the past, plasters were often made with sticky tree resins (such as pine tar). This type of plaster would have to be heated to partially melt the resin so it would be soft enough to conform and adhere to the shape of the patient’s body. One of the problems with medicated plasters is that the adhesive is frequently irritating to the skin and those with body hair often find it quite painful to pull them off!
Traditionally, the making of plasters was a rather involved affair. Making the paste for the plaster was a time consuming process of decocting and concentrating herbs. Pharmacies that made plasters commercially would make large batches, and thus the combination of the large utensils needed for production and the bad smell the emanated from the cooking herbs necessitated moving the production endeavor into a large clearing in the country just outside town. Before beginning the production, an astrologer would be consulted to determine an auspicious day and time, and then prayers for health and good luck were performed.
Gou Pi Gao – Dog Skin Plasters 狗皮膏
Gou Pi Gao is a very well known traditional medicated plaster that is comprised of a very sticky herbal paste spread over a backing of leather, that, as the name suggests, was originally made of dog skin (today the skin is most likely pig or cow). The resinous plaster is so hard that it has to be heated to soften before it can be applied topically. Even removing the plaster involves softening it with heat! These plasters are warming in nature, and are used to treat pain from wind cold damp bi (arthralgia) patterns.
Creams are a commonly used external herbal preparation especially favored in dermatology. A cream is a semi-solid mixture of oil and water (e.g. an emulsion) that is rubbed into the skin. They are different from medicated oils in that oils are liquid at room temperature, and creams are soft solids. Creams are easy to apply and not as messy as medicated oils.
There are literally hundreds if not thousands of commercially available Chinese herbal creams that treat everything from eczema, psoriasis, burns, and other skin disorders, to hemorrhoids or pain conditions. Arguably one of the most famous Chinese herbs worldwide is a type of cream – Tiger Balm. Commonly available even in American supermarkets now, it was developed in the 1870’s by Aw Chu Kin, an herbalist in Burma, and is widely used to treat simple muscle strains. In our office we make injury creams by hand.
Yellow Jade Cream with Added Ingredients – Jia Wei Huang Yu Gao 加味黄玉膏
Ingredients: Huang Lian, Huang Bai, Jiang Can, Ru Xiang, Bai Zhi, Huai Zhi, Bai Xian Pi, Bing Pian, Gan Cao
This cream was once as imperial palace formula kept secret by the Chinese royal family. It is possible that it was prepared to treat variola (smallpox) for the Emperor Tongzhi (1861 – 1875), or to treat the Empress Dowager Cixi’s (1835 – 1908) boils. The herbs in this formula would have been fried in sesame oil and lard before being prepared in the end as a cream for external use.
Soaks, Washes and Compresses
Soaks, washes and compresses are methods of external application that utilize herbs in decoction form, similar to how they would be cooked if taken internally. The raw herb formula is simply boiled for an appropriate amount of time and then the herbs or the resulting liquid that is produced are used on an effected area. Soaks are probably the most commonly applied of this category of external herbs as they are convenient to use and effective. Washes use the same type of decocted formula but are not used to submerge the effected area of the body, but rather wash over the area. A compress is when a cloth is soaked in a medicinal decoction and then held against a part of the body.
These preparations are commonly used to treat musculoskeletal conditions, although their use is not at all limited to treating pain. For example, herbal washes include the use of vaginal douches that are commonly used to treat gynecological conditions. Herbal enemas are given as well to treat gynecological problems, or other disorders of the abdomen, rectum or intestines. Washes and compresses are also effective external therapy for a wide variety of dermatological diseases.
Another variation on the compress is what was described earlier in this article, Hot Pressing. In hot pressing warmed medicinals are applied against the skin. Sometimes when treating muscular skeletal conditions, after herbs are boiled they are then wrapped in a thin towel that is soaked with the resulting liquid from the herb cooking. The herbs in the wet towel are then pressed against the painful area of the body. This method of application is especially useful in treating areas of the body that cannot be soaked because of a difficult location (such as the shoulder or lower back), but that would require longer contact with the medicated liquid than what washing would allow for.
Ingredients: Ku Shen, She Chuang Zi, Huang Bai
These three ingredients are decocted and then strained well. The resulting liquid is used as a vaginal douche to treat yeast infections, vaginal irritation and other causes of vaginitis. Clinical studies have shown that the herbs in this combination have inhibitory effects against Trichomonas vaginalis, and have an antibacterial effect against bacteria such as Staphylococcus aureus.
Aside from douches and enemas, herbs can be prepared as suppositories (either vaginal or rectal). Suppositories are convenient for patients in that there is no cooking or other complex preparation needed as is the case with soaks or washes. They are made by decocting powdered herbs in an oil base that hardens at room temperature. I typically use cocoa butter as a base when I make suppositories because it can be stored at room temperature, but will slowly liquefy at body temperature once it is inserted into the vagina or rectum.
Suppositories are used to treat a wide variety of conditions, including anal problems such as hemorrhoids or fissures, and vaginal problems such as yeast infections. In China, Ku Shen suppositories are widely available and commonly used in TCM hospital gynecology wards.
Liniments and Oils
Liniments are essentially medicated liquors (see part I of this article) that are used topically instead of internally. They are made by steeping an herbal formula in grain alcohol for anywhere from several weeks to several months. The resulting tincture is then rubbed onto the effected part of the body. Liniments are often used along side remedial massage (such as Tuina), and are commonly used to treat musculoskeletal conditions. Since they are easy to make and easy to use, they are convenient for both the practitioner and patient. Liniments are also an easy and safe way to use herbs that would otherwise be extremely toxic for internal use, such as unprocessed Fu Zi (aconite) or Ma Qian Zi (nux vomica).
Medicated oils are made in a similar way in that the herbal formula is steeped in a medium, although in this case oil (such as sesame). Unlike liniments however, medicated oils however are usually made by then heating the oil. Sometimes, powdered herbs are added to oil that is then placed in an oven set at a low temperature (such as 100 degrees centigrade or lower) for 24 to 48 hours. Alternately, the herbs can be placed in the oil that is then heated on a stovetop just below boiling for 4 to 6 hours. In either case, after cooking the herbs are strained. Anytime aromatic substances are used, such as Bing Pian (borneol) or Zhang Nao (camphor), these are stirred into the oil after the rest of the cooking has been finished and it has mostly cooled to room temperature. Like liniments, oils are commonly used along side remedial massage for the treatment of musculoskeletal conditions.
Fumigations (Xun 熏) are when herbs are either burnt or boiled, and the resulting smoke or steam is allowed to wash over the effected area of the body. Although this method of treatment was documented as early as the Ma Wang Dui manuscripts (see above), it is less commonly applied in Oriental medicine clinics in the West. This method is most commonly used to treat conditions such as dermatological disorders or hemorrhoids. For example, the latter can be treated by squatting over decocting Wu Bei Zi, Ku Shen, Huang Bai, Zhi Zi, and Ming Fan, so that the steam bathes the anal region. Fumigations of boiling herbs can also be used to treat pain related conditions.
Moxibustion, the burning of mugwort and other substances, is usually used as a type of heat therapy in conjunction with or separate from acupuncture. Sometimes however, the moxibustion is done so that the smoke of the burning herbs is used as a therapeutic fumigation. For example, in the Jing Yue Quan Shu by Zhang Jie Bin (1563 – 1640), fumigation with the smoke from burning Xiong Huang, Zhu Sha, Xue Jie, Mo Yao and She Xiang is recommended to treat sores and ulcerations. [Please note that this formula contains several toxic ingredients and one ingredient from an endangered animal species and is provided only as an example. It should no longer be applied clinically.]
Ingredients: Ji Xue Teng, Wei Ling Xian, Qiang Huo, Du Huo, Bai Zhi, Bi Ba, Sheng Cao Wu, Sheng Chuan Wu
In 2003 the Journal of Chinese Integrative Medicine published a study describing the treatment of lumbar disc herniation in a series of 107 patients. The above formula was boiled and the stem used as fumigation in conjunction with acupuncture. The effective rate was over 90% in this case series. It is important to note that some of the ingredients in this formula are highly toxic and thus should only be administered under the guidance of a licensed health care provider.
Throughout Chinese history herbs have been used for cosmetic purposes in addition to medical purposes. Thus, in addition to the therapeutic treatments already described in this article, herbs have been incorporated into products for everyday use. As far back as the Ming Dynasty, Li Shi Zhen (1518 – 1593), in his encyclopedic work the Ben Cao Gan Mu (Compendium of Materia Medica), recommended the application of sandalwood to the body for its exquisite yet delicate scent. Soaps have been made with herbs in China for hundreds of years, and such products are still available. Even shampoos and dental products such as toothpastes and toothpowders are made with Chinese herbs.
Medicated Shampoo for the Emperor – Xi Tou Fang Yi 洗头方一
Ingredients: Tian Ma, Sang Ye, Bo He, Bai Zhi, Fang Feng, Qiang Huo, Jin Yin Hua, Chuan Jiao
This medicated shampoo was prepared for the Emperor Guangxu (1971 – 1908). The Emperor frequently suffered form headaches and dizziness, and this formula is used to treat just that. The herbs listed above were decocted in water and then the resulting liquid was used to wash the hair and head.
Moxibustion with Herb Mediums
Moxibustion is a vast subject with a history in Chinese medicine that predates even the use of acupuncture, and thus cannot be explored in depth in the context of this article (for more information on moxibustion see Wilcox 2008). One application of moxibustion however warrants a short discussion here – the use of moxibustion on herbs as isolating substances. In the earliest times, moxibustion was performed with moxa floss (also known as moxa wool) being burned directly on the skin at acupuncture points. But, during the Jin dynasty (263 – 420) the renowned physician Ge Hong (283 – 343), in his book Zhou Hou Bi Ji Fang (Emergency Prescriptions to Keep Up Your Sleeve), described the use of moxibustion on herbs at acupuncture points. In doing so he described for the first time the perfect integration of acupuncture, moxibustion and herbal medicine.
When herbs are used as isolating substances, a slice or small cake of the appropriate herbal material is placed on the skin at the point being treated. A cone of moxa floss is then placed on the herb and burned so the heat is transferred to the point. This method is used for two purposes. First, it buffers the skin so that a burn is less likely (although not impossible), and, second, the heat of the burning moxa is believed to activate the function of the herb so the therapeutic effect is strengthened and made more specific. For example, moxibustion can be done on top of Fu Zi (aconite) cakes or slices to accentuate the function of strengthening the yang qi of the body, or of very strongly warming cold. Moxibustion on fresh ginger slices (Sheng Jiang) strengthens the warming aspect of the therapy, and is especially appropriate in treating weak digestive function. Other materials that have been used for this type of moxibustion include for examples garlic, salt, Sichuan pepper (Hua Jiao), scallion, tangerine peel, or walnut shells.
The herbal formats described in this brief article just barely scratch the surface of how herbs are and can be used externally. As has been discussed, there are many uses for herbs externally in treating orthopedic, dermatological, and internal medicine conditions. In these cases the use of herbs externally can target treatment to a specific area of the body without having to go through general systemic circulation as would be the case with taking formulas internally. Furthermore, using herbs externally allows clinicians to safely use otherwise extremely topic medicinal substances that are useful in treating pain conditions but too dangerous to ingest orally.
Interestingly, as has been alluded to above, the external use of herbs has been favored among physicians employed by ancient Chinese imperial households. Contemporary Chinese medicine scholars hypothesize that the external use of herbs was a sort of cautious move on the part of imperial physicians. Since external herbal therapies have even fewer commonly seen side effects than internal herbal therapies, imperial physicians ran a lower chance of injuring their royal patrons and thereby risking loss of employment or even loss of life. This may be an important avenue of exploration for modern doctors of Chinese medicine as external herbal formulas may be safe but effective options for patients who already may be on heavy doses of western pharmaceuticals alongside which the use of internal herbs may be contraindicated.
In any case, it is still important to remember that herbs in any form should be treated with respect. Patients who are interested in using Chinese herbs of any type should seek out the professional guidance of a licensed health care provider, preferably one certified in Chinese Herbology or in Oriental Medicine by the National Certification Commission for Acupuncture and Oriental Medicine (www.nccaom.org). At the least, this article hopes to expose western audiences to the wide, wide world of Chinese herbal medicines that are rarely seen or prescribed in the west.