【方歌】丹毒名多云片形，风火湿寒肉分凝，胸腹四肢分顺逆，
清火消风砭敷灵。
【注】孙真人云，丹毒一名天火，肉中忽有赤色，如丹涂之状
，其大如掌，甚者遍身，有痒有痛，而无定处。丹名虽
多，其理则一也。形如鸡冠，名鸡冠丹；若皮涩起如麻
豆粒者，名茱萸丹；亦有水丹，遍身起疱，遇水湿搏之
，透露黄色，恍如有水在皮中，此虽小疾，能令人死，
须当速治，不可忽也。色赤者，诸书谓之赤游丹；色白
者，为水丹，小儿多生之。但有干、湿、痒、痛之殊，
有夹湿、夹风、夹寒之别。诸丹总属心火、三焦风邪而
成。如色赤而干，发热作痒，形如云片者，即名赤游丹
，属血分有火而受风也。毒盛者，服蓝叶散；毒轻者，
宜导赤汤加薄荷叶、独活服之。如初起白斑，渐透黄色
，光亮胀坠，破流黄水，湿烂多痛者，名水丹，又名风
丹。多生腿膝，属脾肺有热而夹湿也，宜防己散主之。
亦有起白斑，无热无痛，游走不定者，由火毒未发，肌
肤外受寒郁，名为冷瘼，宜服乌药顺气散，外用姜擦。
凡丹形初见，即用牛、羊精肉片贴之，甚则用砭法，令
出紫血；色重不散者，以柏叶散敷之。又方：云薹叶研
末，靛青调敷甚效。诸丹本于火邪，其势暴速，自胸腹
走于四肢者顺；从四肢攻于胸腹者逆。
方剂：蓝叶散
组成：蓝叶（晒干） 川芎
赤芍 知母
生地 白芷
川升麻 柴胡
葛根 杏仁（炒，去皮、尖）
甘草（生，各一钱） 石膏（〔火段〕）
栀子仁（各五分）
共捣粗末，每用八钱，新汲水二钟，煎八分，去渣
服。热甚，加黄芩、元参。
【方歌】蓝叶散却赤游丹，皆因血热风邪缠，芎芍知膏生地芷，
升麻柴葛杏栀甘。
又方：防己散
组成：防己（三两） 朴硝（一两）
犀角（镑） 川芎
黄芩 黄耆
川升麻（各一钱）
共捣粗末，每用五钱，加竹叶三十片，新汲水二钟
，煎八分服。
【方歌】防己丹毒始白斑，渐黄亮痛湿热原，朴硝犀角芎芩共，
耆与升麻竹叶煎。
又方：乌药顺气散
组成：乌药 橘红（各二钱）
枳壳（麸炒） 白芷
桔梗 防风
僵蚕（炒） 独活
川芎（各一钱） 甘草
水二钟，生姜三片，煎八分服。
【方歌】乌药顺气枳橘红，芷桔风僵独草芎，冷瘼游行无热痛，
因毒未发受寒风。
又方：导赤汤（见口部口糜）
柏叶散（见腰部缠腰火丹）
[Prescription Verse] Dan Du (Erysipelas) has many names, its shape resembling cloud patches. It arises from the coagulation of wind, fire, dampness, and cold pathogens in the muscle layer. One must distinguish between favorable and unfavorable prognoses based on whether it occurs on the chest/abdomen or limbs. Clearing heat, eliminating fire, dispelling wind, and using bloodletting with a stone needle (Bian Fa) combined with topical applications are highly effective.
[Annotation] Sun Simiao stated that Dan Du is also known as "Tian Huo" (Heavenly Fire). A red rash suddenly appears in the skin and muscles, looking like it has been painted with cinnabar. It may be as large as a palm, or in severe cases, cover the entire body. It presents with itching and pain, and the location is not fixed. Although there are many names for Dan Du, the underlying pathology is the same. Those shaped like a rooster's comb are called Ji Guan Dan (Rooster Comb Erysipelas); if the skin is dry and rough with raised bumps like hemp seeds, it is called Zhu Yu Dan (Cornel Erysipelas). There is also Shui Dan (Water Erysipelas), where blisters appear all over the body. When exposed to water and dampness, yellow fluid exudes, giving the appearance of water trapped under the skin. Although this seems like a minor ailment, it can be fatal and requires prompt treatment; it must not be neglected. Those with a red color are referred to in various texts as Chi You Dan (Red Wandering Erysipelas); those with a white color are called Shui Dan, commonly seen in infants. However, there are distinctions in dryness/dampness, itching/pain, and combinations with dampness, wind, or cold. All types of Dan Du generally result from Heart Fire and Wind Pathogens affecting the San Jiao (Triple Burner). For instance, if the color is red and dry, accompanied by fever and itching, with a shape like cloud patches, it is named Chi You Dan. This belongs to Fire in the Blood level complicated by Wind invasion. If the toxicity is severe, Lan Ye San (Isatis Leaf Powder) should be taken; if the toxicity is mild, Dao Chi Tang (Guide Out Redness Decoction) added with Bo He Ye (Mint Leaf) and Du Huo (Angelicae Pubescentis Radix) is suitable. If it begins with white patches that gradually turn yellow, becoming bright, swollen, and heavy, breaking open to flow yellow water, causing damp rot and significant pain, it is named Shui Dan, also known as Feng Dan (Wind Erysipelas). It often occurs on the legs and knees, belonging to Heat in the Spleen and Lung complicated by Dampness. Fang Ji San (Stephania Tetrandra Powder) is the primary prescription. There are also cases starting with white patches, without fever or pain, wandering unpredictably. This is due to Fire Toxicity not yet erupting, while the skin and muscles are constrained by external Cold, named Leng Mo (Cold Miasma). Wu Yao Shun Qi San (Litsea Oil and Qi-Regulating Powder) should be taken, and ginger should be used externally for rubbing. Whenever the initial signs of Dan Du appear, immediately apply slices of lean beef or mutton to the affected area. In severe cases, use Bian Fa (Bloodletting with a Stone Needle) to release purple-black blood. If the discoloration is deep and does not dissipate, apply Bai Ye San (Cypress Leaf Powder) topically. Another prescription: Grind Yun Tai Ye (Artemisia capillaris leaves) into powder, mix with Dian Qing (Indigo Naturalis), and apply topically; this is very effective. All Dan Dus originate from Fire Pathogens, with a rapid onset. Spreading from the chest and abdomen to the limbs is considered a favorable course (Shun); attacking from the limbs to the chest and abdomen is considered an unfavorable course (Ni).
Formula: Lan Ye San (Isatis Leaf Powder)
Composition: Lan Ye (Isatidis Folium, dried), Chuan Xiong (Ligusticum Chuanxiong Rhizoma), Chi Shao (Paeoniae Radix Rubra), Zhi Mu (Anemarrhenae Rhizoma), Sheng Di Huang (Rehmanniae Radix), Bai Zhi (Angelicae Dahuricae Radix), Chuan Sheng Ma (Bupleuri Radix), Chai Hu (Bupleuri Radix), Ge Gen (Puerariae Lobatae Radix), Xing Ren (Armeniacae Semen Amarum, stir-fried, peel and tip removed), Gan Cao (Glycyrrhizae Radix et Rhizoma, raw, 1 qian each), Shi Gao (Gypsum Fibrosum, calcined), Zhi Zi Ren (Gardeniae Fructus, 5 fen each).
Pulverize into coarse powder. Each dose uses 8 qian. Decoct with two zhong of fresh well-water until reduced to eight parts. Strain and take orally. If heat is severe, add Huang Qin (Scutellariae Radix) and Yuan Shen (Ophiopogonis Radix).
[Prescription Verse] Lan Ye San eliminates Chi You Dan, caused by Blood Heat and Wind Pathogen entanglement. Contains Xiong, Shao, Zhi, Gao, Sheng Di, Zhi, plus Sheng Ma, Chai Hu, Ge Gen, Xing Ren, Zhi Zi, and Gan Cao.
Another Formula: Fang Ji San (Stephania Tetrandra Powder)
Composition: Fang Ji (Stephaniae Tetrandrae Rhizoma, 3 liang), Po Xiao (Natrii Sulfas, 1 liang), Xi Jiao (Rhinocerotis Cornu, sliced), Chuan Xiong (Ligusticum Chuanxiong Rhizoma), Huang Qin (Scutellariae Radix), Huang Qi (Astragali Membranacei Radix), Chuan Sheng Ma (Bupleuri Radix, 1 qian each).
Pulverize into coarse powder. Each dose uses 5 qian. Add 30 Zhu Ye (Bambusae Folium) and two zhong of fresh well-water. Decoct until reduced to eight parts and take orally.
[Prescription Verse] Fang Ji San treats early-stage Dan Du with white patches, gradually turning yellow, bright, painful, originating from Damp-Heat. Contains Po Xiao, Xi Jiao, Chuan Xiong, Huang Qin, along with Huang Qi, Sheng Ma, and Zhu Ye decocted.
Another Formula: Wu Yao Shun Qi San (Litsea Oil and Qi-Regulating Powder)
Composition: Wu Yao (Litseae Cubebae Fructus), Ju Hong (Citri Reticulatae Pericarpium Rubrum, 2 qian each), Zhi Ke (Aurantii Fructus Immaturus, stir-bran fried), Bai Zhi (Angelicae Dahuricae Radix), Jie Geng (Platycodonis Radix), Fang Feng (Saposhnikoviae Radix), Jiang Can (Bombyx Batryticatus, stir-fried), Du Huo (Angelicae Pubescentis Radix), Chuan Xiong (Ligusticum Chuanxiong Rhizoma, 1 qian each), Gan Cao (Glycyrrhizae Radix et Rhizoma).
Decoct with two zhong of water and three slices of Sheng Jiang (Zingiberis Rhizoma Recens) until reduced to eight parts and take orally.
[Prescription Verse] Wu Yao Shun Qi San contains Zhi Ke, Ju Hong, Bai Zhi, Jie Geng, Fang Feng, Jiang Can, Du Huo, Gan Cao, and Chuan Xiong. Treats Leng Mo wandering without fever or pain, caused by unmanifested toxicity and exposure to cold wind.
Another Formula: Dao Chi Tang (See Section on Mouth Ulcers)
Bai Ye San (See Section on Flaming Belt Erysipelas)