【方歌】脑疽项正属督脉，左右偏脑太阳经，阳正阴偏分难易，
治与痈疽大法同。
【注】此疽有正有偏，正属督脉经，入发际名为脑疽，俗名对
口；偏属太阳膀胱经，名为偏脑疽，俗名偏对口。正脑
疽系阳亢热极而生，其证多焮赤肿痛，色鲜红活，根束
顶尖，时痛时止。督脉纯阳，草于尾闾，上贯巅顶，挟
毒上升，故易脓、易腐、易敛，多属顺证；若偏脑疽，
系寒热错杂所生，其证漫肿，色暗，平塌，坚硬。然足
太阳经外阳内阴，从头走足，阳降阴凝，难脓、难腐、
难敛，多属逆证。更有兼风湿者，其疮根又易于散大旁
流。故顺逆二证，治法当辨别是痈是疽。脑痈者，皮薄
易破；脑疽者，皮厚难破。初起有表证，令人寒热往来
，宜服荆防败毒散；有里证，令人口唇焦紫，大渴，大
便结燥，宜服内疏黄连汤。若疮势已成，按痈疽肿疡、
溃疡门大法治之。
方剂：荆防败毒散
组成：荆芥 防风
羌活 独活
前胡 柴胡
桔梗 川芎
枳壳（麸炒） 茯苓（各一钱）
人参 甘草（各五分）
姜三片，水二钟，煎八分，食远服，寒甚加葱三枝
。
【方歌】荆防败毒治初疮，憎寒壮热汗出良，羌独前柴荆防桔，
芎枳参苓甘草强。
又方：内疏黄连汤（见肿疡门）
【方歌】脑疽位于项部正中，归属于督脉；偏侧的脑疽位于两侧，归属于足太阳膀胱经。阳证（正脑疽）与阴证（偏脑疽）在病情难易上有所区分，但治疗原则与痈疽的一般大法相同。
【注】这种疽疮有正发和偏发之分。正发的属于督脉经，侵入发际部位，称为“脑疽”，俗称“对口”；偏发的属于足太阳膀胱经，称为“偏脑疽”，俗称“偏对口”。正脑疽是由于阳气亢盛、热邪极盛而生成的，其症状多为红肿灼痛，颜色鲜红鲜活，根部收束、顶端尖锐，疼痛时有时无。因为督脉是纯阳之脉，起于尾闾穴，向上贯穿头顶，挟带毒邪上升，所以容易化脓、容易腐溃、容易愈合，大多属于顺证（预后良好）；如果是偏脑疽，是由于寒热错杂所生成的，其症状表现为漫肿无头，颜色晦暗，平塌不起，质地坚硬。然而足太阳膀胱经外属阳内属阴，经脉从头走向足，阳气下降、阴气凝滞，所以难以化脓、难以腐溃、难以愈合，大多属于逆证（预后不良）。更有兼夹风湿邪气的，其疮疡根部又容易扩散变大并向旁侧流脓。因此，对于顺证和逆证两种情况，治疗方法应当辨别是痈还是疽。脑痈的特点是皮薄，容易破溃；脑疽的特点是皮厚，难以破溃。初起阶段如果有表证，导致患者出现寒热往来交替的症状，适宜服用荆防败毒散；如果有里证，导致患者口唇焦紫、极度口渴、大便干结燥硬，适宜服用内疏黄连汤。如果疮势已经形成，则按照《痈疽肿疡门》和《溃疡门》中的大法则进行治疗。
方剂：荆防败毒散
组成：荆芥、防风、羌活、独活、前胡、柴胡、桔梗、川芎、枳壳（麸炒）、茯苓（以上各一钱），人参、甘草（以上各五分）。生姜三片，水两钟，煎至八分，饭后服用，如果恶寒严重，加葱白三枝。
【方歌】荆防败毒散治疗初起疮疡，缓解憎寒壮热及出汗症状，方中包含羌活、独活、前胡、柴胡、荆芥、防风、桔梗，以及川芎、枳壳、人参、茯苓、甘草以增强疗效。
[Formula Song] Brain carbuncle located at the center of the nape belongs to the Du Meridian (Governing Vessel); lateral brain carbuncles belong to the Foot-Taiyang Bladder Meridian. Yang-type (central) and Yin-type (lateral) differ in difficulty, yet their treatment follows the general principles for sores and ulcers.
[Annotation] This type of carbuncle can be central or lateral. Central cases involve the Du Meridian, penetrating the hairline, and are called "Brain Carbuncle" (Nao Ju), commonly known as "Dui Kou" (Facing Mouth). Lateral cases involve the Foot-Taiyang Bladder Meridian and are called "Lateral Brain Carbuncle" (Pian Nao Ju), commonly known as "Pian Dui Kou". Central brain carbuncles arise from hyperactive Yang and extreme heat; symptoms include intense redness, swelling, and pain, with a fresh red color, a constricted base, and a pointed apex, accompanied by intermittent pain. Since the Du Meridian is purely Yang, originating at the Weilu point (Changqiang, GV-1) and ascending through the vertex, carrying toxic heat upward, it tends to suppurate easily, slough off easily, and heal easily, generally representing a favorable prognosis (Shun Zheng). In contrast, lateral brain carbuncles arise from a mixture of cold and heat; symptoms present as diffuse swelling without a distinct head, dark discoloration, flat collapse, and hardness. As the Foot-Taiyang Meridian is exteriorly Yang and interiorly Yin, running from head to foot, with descending Yang and coagulating Yin, it tends to be difficult to suppurate, difficult to slough, and difficult to heal, generally representing an unfavorable prognosis (Ni Zheng). Furthermore, if complicated by Wind-Dampness, the base of the lesion may spread widely and discharge pus laterally. Therefore, for both favorable and unfavorable conditions, one must distinguish whether it is a carbuncle (Yong) or a deep abscess/carbuncle (Ju). Brain carbuncles (Nao Yong) have thin skin and rupture easily; brain deep abscesses (Nao Ju) have thick skin and are hard to rupture. If there are exterior syndrome patterns at the onset, causing alternating chills and fever, Jingfang Baidu San (Atractylodes and Saposhnikovia Decoction for Overcoming Toxicity) is appropriate. If there are interior syndrome patterns, causing scorched purple lips, extreme thirst, and dry constipation, Neishu Huanglian Tang (Internal Draining Coptis Decoction) is appropriate. Once the lesion has fully formed, treat according to the general principles outlined in the chapters on Sores/Ulcers (Zhongyang) and Ulcers (Kuoyang).
Formula: Jingfang Baidu San (Atractylodes and Saposhnikovia Decoction for Overcoming Toxicity)
Composition: Jingjie (Schizonepetae Spica), Fangfeng (Saposhnikoviae Radix), Qianghuo (Notopterygii Rhizoma et Radix), Duhuo (Angelicae Pubescentis Radix), Qianhu (Peucedani Radix), Chaihu (Bupleuri Radix), Jiegeng (Platycodonis Radix), Chuanxiong (Ligustici Chuanxiong Rhizoma), Zhike (Aurantii Fructus Immaturus, stir-fried with bran), Fuling (Poria), each 1 qian; Renshen (Ginseng Radix), Gancao (Glycyrrhizae Radix et Rhizoma), each 0.5 qian. Add three slices of Shengjiang (Zingiberis Rhizoma Recens), two zhong of water, decoct to obtain eight fen, take after meals. If chills are severe, add three stalks of Congbai (Allii Fistulosi Bulbus).
[Formula Song] Jingfang Baidu San treats initial sores, alleviating aversion to cold, high fever, and sweating; it contains Qianghuo, Duhuo, Qianhu, Chaihu, Jingjie, Fangfeng, Jiegeng, while Chuanxiong, Zhike, Renshen, Fuling, and Gancao strengthen the effect.
Another Formula: Neishu Huanglian Tang (Coptis Decoction for Internal Draining) (See Chapter on Sores/Ulcers)