此乃痈疽中大患，缘其患位，对心对肺对脐耳。偏曰搭手，因手可搭而名。红肿痛甚者
，应
称背痈。治法详于阳症门·痈疖内。如色白肿痛者，当以流注法治。如平塌不痛者，当以阴
疽法治。此皆阴发背也。如误服寒剂，误敷凉药，误贴凉膏，定然毒攻内腑不救。
马曰∶平塌不痛之症颇多，不得均谓之阴疽。凡疽初起，必有头。
凡手足之无名指，患色白而痛甚者，脱骨疽是也。诸书载云∶急剪去指，可保其命，迟
则肿
延手足之背，救无术矣。殊不知此疽也，大人以阳和汤，小孩以小金丹，最狠者以犀黄丸，
皆可以消之。色红者，以热疖、蛇头等法治之。
马曰∶此症无论手足，皆是火毒湿热结成。又有温疫病中，邪陷下焦而成者。阳和汤断
不可投。
又曰∶脱疽无色白者，必现红紫之象，或痛或不痛，或麻木而冷，十指各有主经。何经
受毒
，发于何指。亦有漫延四指者。然多生足指，少毒手指，均是火毒内蕴所致。小金亦非所宜
。
陶曰∶脱骨疽发于脚趾，渐上至膝，色黑，痛不可忍，逐节脱落而死。亦有发于手者。
方用土蜂窠研细，醋调，应手而愈。真神方也。
患生指上，形似蛇头，故名。红肿者，取白萝卜一段，挖孔入雄黄三分，蒸半熟套指。
或取乌梅仁，嚼烂涂指，及嫩膏涂之皆消。如患色白，小金丹服愈。
马曰∶天蛇头即是疔疮，非服小金丹之症。如色白者，是僵节蛀，方可服小金丹，不
可不审也。
这是痈疽病中极为严重的病症，因为其发病部位正对着心、肺和肚脐。如果发生在背部下方，称为“搭手”，是因为患处位置低，手可以搭在上面而得名。如果红肿疼痛剧烈，应当称为背痈。其治疗方法在阳证门·痈疖章节中有详细说明。如果患处颜色发白且肿痛，应当按照流注病的方法治疗。如果患处平塌且不痛，应当按照阴疽病的方法治疗。这些都属于阴发背。如果误服寒凉药物，误敷清凉药膏，误贴凉性膏药，必然导致毒邪攻入内脏而无法救治。
马曰：平塌不痛的病症很多，不能都称之为阴疽。凡是疽病初起，一定会有脓头。
凡是手足的无名指，患病处颜色发白且疼痛剧烈的，就是脱骨疽。各种医书记载说：急忙剪除手指，可以保住性命，拖延则肿胀蔓延至手足背部，就无法救治了。殊不知这种疽病，成年人用阳和汤，小孩用小金丹，病情最严重的用犀黄丸，都可以使其消散。如果患处颜色发红，按照热疖、蛇头等病的方法治疗。
马曰：此症无论发生在手还是脚，都是火毒湿热凝结而成。又有在温疫病中，邪气陷入下焦而形成的。这种情况绝对不可投用阳和汤。
又说：脱疽没有颜色发白的，必定呈现红紫之象，或者痛或者不痛，或者麻木发冷，十个手指各有其所属的主经。哪条经脉受毒，就发于哪个手指。也有蔓延到四个手指的。然而多生于脚趾，少生于手指，都是火毒内蕴所致。小金丹也不适宜使用。
陶曰：脱骨疽发于脚趾，逐渐向上蔓延至膝盖，颜色变黑，疼痛难以忍受，逐节脱落而死。也有发于手上的。方子用土蜂窠研成细末，用醋调匀，涂抹后应手而愈。真是神效的方子。
患处生在手指上，形状像蛇头，所以得名。如果红肿，取一段白萝卜，挖个孔放入三分雄黄，蒸至半熟后套在手指上。或者取乌梅仁，嚼烂涂在手指上，以及嫩膏涂抹，都可以使病灶消散。如果患处颜色发白，服用小金丹可痊愈。
马曰：天蛇头即是疔疮，不是服用小金丹的适应症。如果颜色发白，是僵节蛀（一种坏死性病变），才可以服用小金丹，不可以不仔细审察。
This is a severe condition among carbuncles and sores (Yong Ju), as its location corresponds to the Heart, Lungs, and Umbilicus. When occurring on the lower back, it is called "Da Shou" (Hand-Reaching Carbuncle), named because the hand can reach the affected area. If there is severe redness, swelling, and pain, it should be termed Back Carbuncle (Bei Yong). The treatment methods are detailed in the Yang Syndrome section under Carbuncles and Boils. If the color is white with swelling and pain, it should be treated according to the method for Liu Zhu (Flowing Abscess). If the lesion is flat and painless, it should be treated according to the method for Yin Sore (Yin Ju). These all belong to Yin Back Carbuncle. If cold-natured medicines are mistakenly taken, cooling plasters are mistakenly applied, or cold ointments are mistakenly pasted, the toxin will inevitably attack the internal organs, leading to untreatable conditions.
Ma stated: There are many conditions presenting as flat and painless, which cannot all be classified as Yin Sore. Whenever a sore begins, there must be a head (pustule).
When the ring finger of the hand or foot suffers from whiteness and severe pain, it is Tuo Gu Ju (Bone-Stripping Gangrene). Various medical texts record that if the finger is promptly amputated, life can be saved; otherwise, swelling will spread to the dorsum of the hand or foot, rendering it untreatable. Little do they know that for this type of sore, adults may use Yang He Tang (Cordyceps Decoction), children may use Xiao Jin Dan (Little Golden Pill), and for the most severe cases, Xi Huang Wan (Rhino Horn Pill) can be used to dissipate the lesion. If the color is red, treat it according to the methods for Hot Boils or Snake Head Sores.
Ma stated: This condition, whether on the hand or foot, is formed by the concretion of Fire Toxin, Damp-Heat. It also occurs when pathogenic factors sink into the Lower Jiao during warm epidemic diseases. In such cases, Yang He Tang must absolutely not be administered.
It is further said: Tuo Ju without whiteness will necessarily present with red-purple discoloration, accompanied by either pain or no pain, or numbness and coldness. Each of the ten fingers has its governing meridian. Whichever meridian receives the toxin manifests on that specific finger. It may also spread across four fingers. However, it mostly occurs on the toes and rarely on the fingers, both caused by the internal accumulation of Fire Toxin. Xiao Jin Dan is also inappropriate here.
Tao stated: Tuo Gu Ju begins on the toes, gradually spreading up to the knee, turning black, with unbearable pain, leading to death as joints fall off sequentially. It can also occur on the hands. The prescription uses earth bee nests ground into fine powder, mixed with vinegar, which heals upon application. Truly a miraculous prescription.
The lesion occurs on the finger, resembling a snake's head, hence the name. If red and swollen, take a segment of white radish, hollow out a hole, insert 3 fen of Realgar (Xiong Huang), steam until half-cooked, and fit it over the finger. Alternatively, take the kernel of a Chinese Plum (Wu Mei), chew it thoroughly, apply it to the finger, along with tender plaster, which will cause the lesion to dissipate. If the lesion is white, taking Xiao Jin Dan will lead to recovery.
Ma stated: Tian She Tou (Heavenly Snake Head) is essentially Ding Chuang (Ding Carbuncle/Furuncle), not a condition suitable for Xiao Jin Dan. If the color is white, indicating Jiang Jie Zhu (Stiff Joint Rot/Necrosis), then Xiao Jin Dan can be taken. One must not fail to examine this carefully.