火丹者，心火妄动，三焦风热乘之，故发于肌肤之表，有干湿不同，红白之异。干者色红，形如云片，上
起风粟，作痒发热，此属心、肝二经之火，治以凉心泻肝，化斑解毒汤是也。湿者色多黄白，大小不等，流水
作烂，又且多疼，此属脾、肺二经湿热，宜清肺、泻脾、除湿，胃苓汤是也。腰胁生之，肝火妄动，名曰缠腰
丹，柴胡清肝汤。外以柏叶散、如意金黄散敷之。
化斑解毒汤
化斑解毒汤石膏 玄参知母共连翘
黄连升麻蒡子等 甘草人中黄更高
治三焦风热上攻，致生火丹，延及遍身痒痛者。
玄参 知母 石膏 人中黄 黄连 升麻 连翘 牛蒡子（各等分） 甘草（五分）
水二钟，淡竹叶二十片，煎八分，不拘时服。
除湿胃苓汤
除湿胃苓汤草朴 陈皮二术泽猪苓
防风滑石山栀等 木通薄桂赤苓名
治脾、肺二经湿热壅遏，致生火丹作烂疼痛者。
防风 苍术 白术 赤茯苓 陈皮 浓朴 猪苓 山栀 木通 泽泻 滑石（各一钱） 甘草 薄桂（各三分）
水二钟，灯心二十根，煎八分，食前服。
柏叶散
柏叶散中蚯蚓粪 赤豆大黄君莫混
加上黄柏轻粉霜 水调敷上何须问
治三焦火甚致生火丹，作痒或作痛，延及遍身。
侧柏叶（炒黄为末，五钱） 蚯蚓粪（韭菜田内者佳） 黄柏 大黄（各五钱） 赤豆 轻粉（各三钱）
上为细末，新汲水调搽。
缠腰火丹，方用宝钞一张，烧化存性，研为细末，用米醋调稀，鸡翎蘸涂患上，一日三次即愈。忌食发物。
如意金黄散（见肿疡门）
治火丹不论新久痒痛，用新汲水调敷，靛汁亦好。
火丹，是由于心火妄动，三焦风热侵袭所致，因此发作于肌肤表面，分为干性和湿性两种，颜色有红色和白色的区别。干性的表现为皮肤发红，形状像云片一样，上面起风疹粟粒，伴有瘙痒和发热，这属于心和肝两经的火邪，治疗应当清心泻肝、化斑解毒，使用化斑解毒汤。湿性的表现多为黄白色，大小不等，流水糜烂，且多伴有疼痛，这属于脾和肺两经的湿热，适宜清肺、泻脾、除湿，使用胃苓汤。如果火丹生在腰胁部，是肝火妄动所致，名叫缠腰丹，用柴胡清肝汤治疗。外用柏叶散或如意金黄散敷贴。
化斑解毒汤
组成：石膏、玄参、知母、连翘、黄连、升麻、牛蒡子等，甘草用量更高。
主治：治疗三焦风热上攻，导致生火丹，蔓延至全身并出现瘙痒疼痛的症状。
处方：玄参、知母、石膏、人中黄、黄连、升麻、连翘、牛蒡子（各等分），甘草（五分）。
用法：水两钟，淡竹叶二十片，煎至八分，不拘时候服用。
除湿胃苓汤
组成：甘草、厚朴、陈皮、苍术、白术、泽泻、猪苓、防风、滑石、山栀、木通、薄桂、赤茯苓。
主治：治疗脾、肺两经湿热壅遏，导致生火丹并出现糜烂疼痛的症状。
处方：防风、苍术、白术、赤茯苓、陈皮、厚朴、猪苓、山栀、木通、泽泻、滑石（各一钱），甘草、薄桂（各三分）。
用法：水两钟，灯心草二十根，煎至八分，饭前服用。
柏叶散
组成：侧柏叶、蚯蚓粪、赤豆、大黄、黄柏、轻粉。
主治：治疗三焦火盛导致生火丹，出现瘙痒或疼痛，蔓延至全身。
处方：侧柏叶（炒黄研末，五钱）、蚯蚓粪（以韭菜田内的为佳）、黄柏、大黄（各五钱）、赤豆、轻粉（各三钱）。
用法：以上药物研为细末，用新汲水调匀后搽涂患处。
Huodan (Fire Erysipelas) is caused by the reckless movement of Heart Fire and Wind-Heat invading the Sanjiao (Triple Burner), thus manifesting on the surface of the skin. It presents in dry and wet forms, with variations in red and white colors. The dry type manifests as red skin resembling cloud patches, raised wind-corns (urticarial papules), accompanied by itching and fever; this belongs to Fire in the Heart and Liver meridians, and should be treated by cooling the Heart and purging the Liver, resolving macules, and detoxifying, using Huaban Jiedu Tang (Macule-Resolving Detoxification Decoction). The wet type appears mostly yellowish-white, varying in size, weeping fluid and causing erosion, often with significant pain; this belongs to Damp-Heat in the Spleen and Lung meridians, and should be treated by clearing the Lungs, purging the Spleen, and removing Dampness, using Weiling Tang (Stomach-Purging Decoction). If it occurs on the waist and hypochondrium due to reckless Liver Fire, it is called Chanyao Dan (Waist-Coiling Erysipelas), treated with Chaihu Qinggan Tang (Bupleurum Liver-Clearing Decoction). Externally apply Baiye San (Cypress Leaf Powder) or Ruyi Jinhuang San (Ruyi Golden Yellow Powder).
Huaban Jiedu Tang (Macule-Resolving Detoxification Decoction)
Composition: Shigao (Gypsum Fibrosum), Xuanshen (Scrophulariae Radix), Zhimu (Anemarrhenae Rhizoma), Lianqiao (Forsythiae Fructus), Huanglian (Coptidis Rhizoma), Shengma (Cimicifugae Rhizoma), Niubangzi (Arctii Fructus), etc., with Gancacao (Glycyrrhizae Radix et Rhizoma) used in a higher proportion.
Indications: Treats Huodan caused by Wind-Heat attacking upward from the Sanjiao, spreading over the whole body with itching and pain.
Prescription: Xuanshen, Zhimu, Shigao, Renzhonghuang (Human Feces Carbonized), Huanglian, Shengma, Lianqiao, Niubangzi (each equal parts), Gancacao (2 grams).
Administration: Water 600 ml, Danzhuye (Lophatheri Herba) 20 leaves, decocted to 240 ml, taken at any time.
Chushi Weiling Tang (Damp-Removing Stomach-Purging Decoction)
Composition: Gancacao, Houpo (Magnoliae Officinalis Cortex), Chenpi (Citri Reticulatae Pericarpium), Cangzhu (Atractylodis Rhizoma), Baizhu (Atractylodis Macrocephalae Rhizoma), Zexie (Alismatis Rhizoma), Zhuling (Polyporus), Fangfeng (Saposhnikoviae Radix), Huashi (Talcum), Zhizi (Gardeniae Fructus), Mutong (Akebiae Caulis), Bo Gui (Cinnamomi Cortex), Chi Fuling (Poria Cocos with Red Mycelium).
Indications: Treats Huodan with erosion and pain caused by Damp-Heat stagnation in the Spleen and Lung meridians.
Prescription: Fangfeng, Cangzhu, Baizhu, Chi Fuling, Chenpi, Houpo, Zhuling, Zhizi, Mutong, Zexie, Huashi (each 3 grams), Gancacao, Bo Gui (each 1 gram).
Administration: Water 600 ml, Dengxincao (Junci Medullia) 20 stems, decocted to 240 ml, taken before meals.
Baiye San (Cypress Leaf Powder)
Composition: Cebaiye (Platycladi Cacumen), Qiuyinfen (Earthworm Excrement), Chidou (Vigna Angularis Semen), Dahuang (Rhei Radix et Rhizoma), Huangbai (Phellodendri Cortex), Qingfen (Calomelas).
Indications: Treats Huodan caused by excessive Fire in the Sanjiao, presenting with itching or pain, spreading over the whole body.
Prescription: Cebaiye (stir-fried until yellow and powdered, 15 grams), Qiuyinfen (preferably from leek fields), Huangbai, Dahuang (each 15 grams), Chidou, Qingfen (each 9 grams).
Administration: Grind all ingredients into fine powder, mix with fresh well water, and apply externally.
For Chanyao Huodan (Waist-Coiling Fire Erysipelas), use one banknote, burn it to ash while preserving its medicinal nature, grind into fine powder, mix with rice vinegar to a thin consistency, dip a chicken feather in the mixture, and apply to the affected area three times a day for cure. Avoid stimulating foods (Fa Wu).
Ruyi Jinhuang San (Ruyi Golden Yellow Powder) (See Swelling and Ulcer Section)
Indications: Treats Huodan regardless of new or old onset, with itching and pain. Mix with fresh well water for external application; Indigo juice is also effective.