The Medicinal Pair for Scrofula (Lymphatic Tuberculosis): Qumai (Dianthi Herba) and Lianqiao (Forsythiae Fructus)
In the entry on "scrofula syndrome" (luoli zheng) in Li Dongyuan's Essentials of Practical Methods (Huofa Jiyao), there are a total of three treatment prescriptions, two of which are composed primarily of Qumai (Dianthi Herba) and Lianqiao (Forsythiae Fructus).
Prescription 1: one jin each of Lianqiao and Qumai flower, three liang of Dahuang (Rhei Radix et Rhizoma), and two liang of Gancao (Glycyrrhizae Radix et Rhizoma). Decoct in water and take orally.
Prescription 2: one jin of Lianqiao and half a jin of Qumai spike. Crush the above into coarse granules, decoct in water, and take before bedtime. Li Dongyuan appended a note to this entry: "The efficacy of this medicine, when it takes effect, often does not manifest quickly; recovery should be expected only after a long period of time."
Regarding "scrofula syndrome," Li Dongyuan explained as follows: "What is called scrofula refers to tuberculous lumps. Whether behind the ear, in front of the ear, below the ear extending to the cheek and jaw, or below the neck extending to the supraclavicular fossa, all are termed scrofula; whether on the chest or the sides of the chest, or on both flanks, all are termed madao ('horse-knife' scrofula). It is governed by the Hand-Shaoyang and Foot-Shaoyang meridians."
This description matches the clinical features of lymphatic tuberculosis. According to modern medical research, lymphatic tuberculosis is lymph node enlargement caused by infection with Mycobacterium tuberculosis; the most common site of lesion is the neck, though it may also appear in the lymph nodes of the chest and hypochondrium. Under the skin, lymphatic tuberculosis appears in a beaded chain, may be accompanied by pain, and may discharge pus when ulcerated. Western medicine treats this disease mainly through anti-tuberculosis therapy.
Traditional Chinese medicine has shortcomings in the treatment of tuberculosis. Pulmonary tuberculosis is known in TCM as feilao (pulmonary consumption), and it is one of the four major incurable diseases of TCM internal medicine. Lymphatic tuberculosis and pulmonary tuberculosis share the same cause—both result from infection with Mycobacterium tuberculosis—and among Chinese materia medica there is no clearly anti-tuberculosis drug. Li Dongyuan himself stated bluntly that "the efficacy of this medicine, when it takes effect, often does not manifest quickly; recovery should be expected only after a long period of time," indicating that the course of treatment for this disease is long.
Lianqiao is the most commonly used medicinal in TCM external medicine; it has the actions of clearing heat, detoxifying, reducing swelling, and dissipating nodules. Modern research shows that Lianqiao has antibacterial, anti-inflammatory, antipyretic, and antitumor effects, but it is by no means a specific drug against Mycobacterium tuberculosis. Qumai is a commonly used diuretic and stranguria-relieving herb in Chinese medicine; it also has some blood-activating and stasis-resolving action, but its primary effect lies in promoting diuresis.
The pairing of Lianqiao and Qumai, according to TCM prescription principles, belongs to the "clearing method" (qingfa) among the eight therapeutic methods: on the one hand it clears heat, detoxifies, reduces swelling, and dissipates nodules, and on the other it promotes urination, giving the pathogenic evil a route of exit so that it is discharged from the body. However, the true mechanism by which such a formula treats lymphatic tuberculosis may be difficult to elucidate through research.
In the other prescription, Dahuang and Gancao are added. In my view, this is not suitable for long-term use; it is acceptable for a patient with constipation to take it briefly for three to five days, but prolonged use can easily cause habitual constipation. This is because Dahuang (rhubarb) has a two-way action: taken short-term it purges the bowels, but taken long-term it tends to cause habitual constipation.