陆氏九芝曰∶丹痧斑疹四者，丹与痧类，斑与疹类，痧轻而丹重，疹轻而斑重，丹与斑
皆出与肤平而成片，痧与疹皆高出于肤而成点。痧自痧，丹自丹也浑言之则通曰痧，亦疹
自疹，斑自斑也，浑言之则通曰疹。而痧之原出于肺，因先有痧邪而始发表热，治痧者当治
肺，以升达为主，而稍佐以清凉。疹之原出于胃，因表热不解已成里热而蕴为疹邪，治疹者
当治胃以清凉为主而少佐以升达。痧于当主表散时不可早用寒泻，疹于当主苦泄时不可
更从辛散。大旨升达主升麻葛根柴之属，清凉主芩栀桑丹之属，惟宗仲景葛根芩连一法出
入增减，则于此际之细微层折皆能曲中而无差忒，此治痧疹之要道也。自来治此证者主辛
散则禁寒泄，主寒泄则禁辛散，故两失之至，不仅为痧与疹，而为丹为斑则皆里热之甚，惟
大剂寒药乃克胜任，非第痧疹之比矣。有是四者脘必闷，四者之齐与不齐以脘闷之解与未
解为辨。有是四者热必壮，四者之解与不解以汗出之透与未透为辨。故当正治痧疹时必兼
行升清两法，表里交治，务使痧疹与汗并达。惟痧疹当发出之际，病患每闷极不可耐，稍一
辗转反侧其点即隐，病邪反从内陷，此正不必有外来之风也，即袖端被角间略有疏忽其汗
便缩，一缩之后旋即周身皆干。此时厥有二毙，一则汗方出时毛孔尽开新风易入，一则汗
已大出不可再汗。非特痧疹立隐，且津液既泄，热必益炽，后此变端，皆从此起。病家只道
未愈，医者亦但说变病，孰知皆汗不如法之故耶。凡病之宜从汗解者无不皆然，而兼痧疹者
尤甚。故特于此发之。
陆九芝先生说：丹、痧、斑、疹这四种病症，丹和痧属于同类，斑和疹属于同类。痧症较轻而丹症较重，疹症较轻而斑症较重。丹和斑都平出于皮肤表面并连成片状，痧和疹都高出皮肤表面并形成点状。痧就是痧，丹就是丹，笼统地说可以通称为痧；疹就是疹，斑就是斑，笼统地说可以通称为疹。
然而，痧的根源在于肺，因为先有痧邪侵袭才出现表热症状，治疗痧症应当治肺，以升发透达为主要方法，并稍加配合清凉药物。疹的根源在于胃，因为表热未解已发展为里热，蕴结成为疹邪，治疗疹症应当治胃，以清凉为主，并少量佐以升发透达的药物。
在应当主用表散法时，治疗痧症不可过早使用寒凉泻下之法；在应当主用苦寒泄热时，治疗疹症不可再从辛温发散入手。大概而言，升发透达主要指升麻、葛根、柴胡这一类药物；清凉主要指黄芩、栀子、桑叶、牡丹皮这一类药物。只要遵循张仲景《伤寒论》中葛根芩连汤这一法则进行出入增减变化，就能对此时病情的细微曲折之处准确把握而无差错，这是治疗痧疹的关键所在。
自古以来治疗这类病症的人，主张辛温发散的就禁止使用寒凉泻下，主张寒凉泻下的就禁止使用辛温发散，因此两者都失之偏颇。至于丹和斑，则都是里热极盛的表现，只有用大剂量的寒凉药物才能胜任，这就不只是痧和疹所能比拟的了。
凡是患有这四种病症之一，胸脘部必然感到闷堵。判断这四种病症是否消退，以胸脘部的闷堵感是否解除为辨别标准。凡是患有这四种病症之一，发热必然壮盛。判断这四种病症是否痊愈，以汗出是否透彻为辨别标准。
因此，在治疗痧疹的正治过程中，必须同时运用升清透达和清热两法，表里同治，务必使痧疹与汗液一同透发出来。只是在痧疹应当发出的时候，患者往往因胸闷极度难受，稍微翻动身体，疹点就会隐没，病邪反而向内陷入。这并不一定是外来的风邪所致，即使是衣袖或被角间略有疏忽，导致汗液收敛，一旦汗缩之后，随即全身都会变得干燥。
此时会出现两种致命的危险：一是汗刚发出时毛孔全部张开，新风容易侵入；二是大汗已经流出，不可再次发汗。不仅痧疹会立即隐没，而且津液既然已经耗泄，热势必定更加炽盛，此后的各种变证，都由此引起。病人只认为病没有好，医生也只说是发生了变证，谁又知道这都是因为发汗不得法的缘故呢？
Mr. Lu Jiuzhi stated: Among the four conditions—danzha (scarlet fever-like rash), shazhen (shagreen and maculopapular rash), ban (maculae), and zhen (papules)—dan and shazhen are of the same category, while ban and zhen are of the same category. Shazhen is mild whereas dan is severe; zhen is mild whereas ban is severe. Dan and ban emerge flat upon the skin surface forming patches, whereas shazhen and zhen protrude above the skin surface forming dots. Shazhen is shazhen, dan is dan; generally speaking, they may be collectively referred to as shazhen. Zhen is zhen, ban is ban; generally speaking, they may be collectively referred to as zhen.
However, the origin of shazhen lies in the Lung (Zang organ). Because pathogenic shazhen factors are present first, exterior heat symptoms appear. To treat shazhen, one should target the Lung, primarily employing methods of ascending and venting (releasing pathogens from the exterior), with a slight addition of cooling agents. The origin of zhen lies in the Stomach (Zang organ). Because exterior heat has not resolved and has transformed into interior heat, accumulating to form pathogenic zhen factors, to treat zhen, one should target the Stomach, primarily employing cooling methods, with a minor addition of ascending and venting agents.
When the primary treatment should be exterior dispersing, cold purgatives must not be used too early for shazhen. When the primary treatment should be bitter cold draining,辛散 (acrid dispersing) methods must not be employed again for zhen. Generally speaking, ascending and venting mainly refers to herbs such as Shengma (Cimicifugae Rhizoma), Gegen (Puerariae Lobatae Radix), and Chaihu (Bupleuri Radix); cooling mainly refers to herbs such as Huangqin (Scutellariae Radix), Zhizi (Gardeniae Fructus), Sangye (Mori Folium), and Mudanpi (Moutan Cortex). As long as one follows the principle of Gegen Qinlian Tang (Kudzu and Scutellaria Decoction) established by Zhang Zhongjing, making appropriate modifications, one can accurately address the subtle nuances of the condition at this stage without error. This is the essential approach to treating shazhen.
Historically, those treating these conditions have either advocated acrid dispersing and prohibited cold purging, or advocated cold purging and prohibited acrid dispersing, thus failing in both aspects. Regarding dan and ban, however, they represent extreme interior heat. Only large doses of cold medicines can effectively handle them; they cannot be compared merely to shazhen and zhen.
For any of these four conditions, there will inevitably be chest and epigastric stuffiness. Whether these four conditions are resolving or not is distinguished by whether the chest and epigastric stuffiness has resolved or not. For any of these four conditions, the fever will necessarily be vigorous. Whether these four conditions are resolving or not is distinguished by whether sweating is thorough or not.
Therefore, when conducting standard treatment for shazhen, one must simultaneously employ both ascending/clearing and cooling methods, treating both the exterior and interior, ensuring that the shazhen and sweat emerge together. However, when shazhen is at the stage of eruption, patients often suffer from unbearable chest stuffiness. If they move even slightly, the spots may retract, and the pathogenic factors may sink inward. This does not necessarily imply an external wind pathogen; even slight negligence regarding sleeves or blankets can cause sweat to recede. Once sweat recedes, the entire body quickly becomes dry.
At this point, two fatal dangers arise: first, when sweat just begins to emerge, pores open completely, allowing new wind pathogens to easily enter; second, after profuse sweating, further sweating is contraindicated. Not only will the shazhen immediately retract, but since fluids have been depleted, heat will become even more intense. All subsequent complications arise from this. Patients believe the illness is unresolved, and physicians attribute it to disease transformation, unaware that it is due to improper sweating management.
This applies to all diseases suitable for resolution through sweating, but is particularly critical in cases complicated by shazhen. Therefore, this issue is specifically highlighted here.