Dai Dao San (Scalpel-Replacing Powder) for Draining Pus and Relieving Pain
In Waike Zhengzhi Quansheng Ji (Records of Comprehensive Sage-Style External Medicine) there is a formula named Dai Dao San (Scalpel-Replacing Powder), composed of "Zaojiao Ci (Gleditsiae Spina) and Mian Huangqi (astragalus) each one liang (stir-fried), Sheng Gancao (raw licorice) and Ruxiang (Olibanum) each five qian." These are ground together into a powder; each dose is three qian, taken with wine. This formula has the effects of supporting toxin and draining pus, and scattering stasis and relieving pain. It governs carbuncles and swollen toxins, diffuse swelling with no head, or hard nodules that fail to form pus, or pus that has formed but cannot rupture.
How do we tell whether a swollen lesion has pus? According to the experience of Duan Futing, a celebrated master of Chinese external medicine: any swollen lesion that feels hot and throbs, and which dimples on pressure and rises back when the hand is removed, is evidence of pus. This means the lesion feels hotter than the rest of the body surface, there is throbbing pain inside, and when pressed with a finger it dimples — that is evidence of pus. However, when pus is just forming, pressing may not dimple the lesion, which may remain very hard. In the author's clinical experience, the key signs of presence or absence of pus are whether the overlying skin is hot and whether the lesion throbs.
Master Duan further said: pain on light pressure means pus is superficial; pain only on heavy pressure means the pus must be deep; quick rebound on deep pressure indicates watery material, while slow rebound indicates putrid, acrid-smelling pus. Master Duan considered suppuration of swollen lesions a common external-medicine phenomenon: carbuncles and sores, after rupture, usually first discharge thick yellow-white pus, then after several days peach-colored pus, and finally pale yellow serous fluid; once flesh grows and skin closes, healing follows — this is a good prognosis. If the pus is white and thin and not foul-smelling, it indicates the patient is weak and needs a supplementing approach. Thin pus mixed with white putrid fragments belongs to deficiency-phlegm and is difficult to treat. Pus mixed with blood indicates injured sinew and blood stasis. Pus discharged as filthy as dirty sewage, or fishy and foul as silt, is putrid, acrid-smelling pus; putrid pus indicates a severe depletion of righteous qi and is an untreatable condition.
In the past, how did external medicine treat suppurating swollen lesions? Some doctors advocated using a needle or scalpel to draw pus outward; the Ming-dynasty external master Chen Shigong, for example, often drained pus for patients. Others advocated taking Chinese medicine internally — the very name Dai Dao San ("scalpel-replacing powder") shows its action is to replace the knife and needle, draining pus through oral herbs. Modern medicine is more advanced: if the patient's suppuration is caused by infection, antibiotics usually solve the problem. If the lesion is very severe and may cause serious infection, surgical removal of the focus is needed. If the pus comes from a ruptured tumor with a poor prognosis, such as breast cancer, a comprehensive anticancer regimen is required; when a cancerous mass suppurates, relying alone on formulas like Dai Dao San is not effective.
Formulas like Dai Dao San are mainly for resolving suppurative infections; treating suppuration after cancerous ulceration is not their forte. However, some cancerous suppurations are also caused by infection, in which case Dai Dao San may still have some effect.
Huangqi in this formula is considered in TCM to supplement qi; it is an important herb for supporting toxin and draining pus. Pus should be expelled as quickly as possible, so Huangqi is used in large doses to support toxin and drain pus. In the author's experience, a large dose of Huangqi helps close ulcers that will not heal. Zaojiao Ci is the key herb for resolving swelling, supporting toxin, and draining pus; used here together with Huangqi, it combines dispersing and supplementing in one formula. Sheng Gancao clears heat and resolves toxin while relieving pain; Ruxiang activates blood, resolves stasis, and fixes pain. These four herbs together produce the effect of draining pus and relieving pain. Later generations sometimes added herbs such as Baizhi (Angelicae Dahuricae Radix) to strengthen the pus-draining and pain-relieving action.
Formulas like Dai Dao San should not be used long-term; they follow the TCM principle of "stop once the disease is addressed." Once effective, do not continue taking them, or the righteous qi will be damaged. This formula is also not suitable for pregnant women.