By Heiner Fruehauf

Gancao Xiexin Tang was first recorded by the Han physician Zhang Zhongjing about 1,800 years ago. Both Shanghan lun and Jingui yaolüe, the now separated parts of his classic guidebook on herbal formulas (Shanghan zabing lun), cite this particular formula.

In modern times, this formula is usually regarded as a variation of the widely used Pinellia Purge the Heart Decoction (Banxia Xiexin Tang) and thus most often prescribed as a remedy for Banxia Xiexin Tang symptom complex (discomfort in stomach area, belching, diarrhea). This is precisely the usage suggested for this remedy in the Shanghan lun, where Gancao Xiexin Tang and Shengjiang Xiexin Tang are listed as variations of the standard Banxia Xiexin Tang.

Most Chinese medicine practitioners are not aware, however, that Gancao Xiexin Tang appears by itself in the Jingui yaolüe, where it is recommended for an entirely different condition. The Jingui formula, different from its first appearance in the Shanghan lun, uses raw licorice rather than baked licorice, which makes the formula primarily a remedy against “poisonous” conditions. It appears as the standard remedy in the chapter “Huhuo Disease,” an affliction which is described as follows:

Patients with Huhuo Disease (literally Fox and Vermin Disease) exhibit symptoms that are not unlike feverish diseases: listless depression with a desire to sleep, but not being able to close the eyes, and restlessly getting up and laying down again. A worm afflicting the throat is called huo (vermin), and a worm afflicting the anus and genitals is called hu (fox). Patients typically have no desire to eat or drink, express an aversion to the smell of food or unpleasant odors, and their face color changes from red to dark to white. If the worm is afflicting the upper part, patients may experience loss of voice. For this type of condition use Gancao Xiexin Tang: Gancao (4 liang)  Huangqin (3 liang)  Renshen (3 liang)  Ganjiang (3 liang)  Huanglian (1 liang)  Dazao (12 pieces)  Banxia (1/2 sheng). [Transmission varies about whether there is renshen/ginseng in the formula or not]

Ever since the Jingui was rediscovered during the Tang dynasty, there has been a lively discussion about the interpretation of Huhuo Disease. Most interpreters agree that the “worm” affliction has to be understood as some kind of metaphorical “poison” rather than a worm that can be detected by the physician’s eyes. Mentioning of the “Fox”–an obvious metaphor used by Zhang Zhongjing to describe the tendency of the disease causing agent to creep into moist dark holes like a fox–seems to corroborate this assertion.

The Tang physician Sun Simiao, in his influential medical compendium Qianjin yaofang, points out that “Huhuo Disease is caused by heat poison,” and Qin Bowei, one of the most acclaimed Chinese medical theoreticians of the 20th century, adds that “Huhuo was some kind of elusive animal to ancient people, thus they used this term as a metaphor to describe a disease which would progress in unprecedented ways.”

Throughout Chinese medical history, therefore, the formula was considered the primary treatment for patients with “poisonous” skin diseases involving the eyes, mouth, anus, and genitals. Furthermore, an analysis of the words “hu” and “huo” as they were used during and before Zhang Zhongjing’s time, associates them with sexual promiscuity, a strong indication that Zhang Zhongjing might have referred to a sexually transmitted disease.

Recent interpretations of Huhuo Disease thus include syphilis, a theory first mentioned by the renowned Jingui expert and early pioneer of combined TCM/Western therapy, Cao Yingpu, who successfully used Pinellia and Licorice Combination for this disease in 1930′s Shanghai. In 1950′s and 1960′s Chengdu, moreover, patients with syphilitic lesions used to see the legendary tea house doctor and Jingui expert Dr. Tian Heming, who was said to have a highly effective cure against the malaise. Similar to Cao Yingpu, Tian used a fortified version of Gancao Xiexin Tang and reportedly achieved extraordinary results.

Mainland Chinese medical authorities have recently concluded with patriotic pride that Huhuo Disease is Behcet’s Syndrome, a autoimmune disease involving ulcerations of the eyes, mouth, genitals and GI tract that was discovered in the West only in 1937.

The Sichuan physician Dr. Zeng Rongxiu, the last practicing student of Tian Heming and now himself known as a Shanghan veteran, is a good example for the contemporary application of Gancao Xiexin Tang. Known for his treatment of “difficult and recalcitrant diseases,” he considers this formula as one of his primary remedies. In general, he treats all kinds of skin diseases, such as eczema, allergic skin reactions, neurodermatitis, etc., with Gancao Xiexin Tang:

(Sheng) Gancao (Licorice, raw) 15g
Banxia (Pinellia) 9g
Huangqin (Scutellaria) 9g
Huanglian (Coptis) 6g
Ganjiang (Ginger, dried) 6g
Dazao (Jujube) 9g

His recommendations for modifications are as follows: for evidence of “poison” (red, itching), add Jinyinhua (Lonicera, 12g), Tufuling (Smilax, 12g), Xuanshen (Scrophularia, 12g); for stubborn or chronic conditions, add Taoren (Persica, 9g), Honghua (Carthamus, 9g), and potentially Dibiechong (Eupolyphaga, 9g); for obvious blood heat, add Mudanpi (Moutan, 9g); for poor appetite, add Shanzha (Crataegus, 9g), Shenqu (Massa fermentata, 9g), (chao) Maiya (fried Barley sprouts, 9g), (chao) Guya (fried Rice sprouts, 9g).