麻疹，乃六腑肠胃之热蒸于肺，外感内伤并发。与痘疹表似同里实异。初热三日，出胀共三日，
出而又没，没而又出，一周时许。重者，遍身绷胀，眼亦封闭。有赤白微黄不同，仍要红活，最嫌
黑陷及面目、胸腹稠密，咽喉攒缠者逆。发不出而喘者，即死。与大科瘾疹相似，又与发斑相似，
如锦纹，有空缺处，如云头状。麻即如麻，遍身无空，但疏密不同耳，仍有夹斑、夹丹、夹疮同出者。
初起，呵欠、发热、恶寒、咳嗽、喷嚏、流涕、头眩，宜升麻葛根汤加紫苏、葱白以解肌。
切忌大汗。斑不红者亦宜。乃麻痘初起之神方。潮热甚，加芩连地骨皮；谵语调辰砂、六一散；咳嗽
加麻黄、杏仁、麦冬、石膏；咳甚，另用凉膈散加桔梗、地骨皮；泄泻宜四苓散；便血合犀角地黄汤；
吐、衄血加炒山栀；不便赤加木通；寒热似疟，小柴胡汤。
初起全类伤寒，但面赤、中指冷为异耳。
已出烦躁作渴者，解毒汤合白虎汤；喘便闭者，前胡枳壳汤加赤茯苓、大黄、甘草、五味，水煎服；
便闭三四日者，小承气汤、防风通圣散；谵语尿闭者，导赤散；如泔者，四苓散加车前、木通；谚语如
狂者，解毒汤调辰砂六一散；大便血、小便亦见血者，犀角地黄汤合解毒汤；吐血衄血，解毒汤加炒山
栀、童便；泄泻，解毒汤合四苓散；喘兼泄泻溺涩者，柴苓汤；烦渴、吐、作泻者，白虎汤加苍术、猪苓汤；
热盛干呕，解毒汤；伤食呕吐，四君子汤；夏月因暑作呕，
四苓散加人参。忌用豆蔻、木香、姜、桂热药。
麻症初起，已出已没及一切杂症，与痘毒大同，但始终药宜清凉。虽麻喜清凉、痘爱温暖，不易常
道，虚则补，实则泻，医家活法。故治麻亦有血虚而用四物汤，气虚用四君子汤，天寒伤冷则温中、理
中之药，一时之权变用也。
麻症没后，余热内攻，循衣摸床、谵言妄语。神昏丧志者死。如热轻，余毒未除，必先见诸气色，
虽预防之始终，以升麻葛根汤为主，或消毒饮、解毒汤，随症选用。仍忌鱼腥葱蒜之物。
升麻葛根汤（方见痘疮。）
辰砂六一散（即益元散，方见中暑。）
凉膈散（方见火证。）
四苓散（即五苓散，方见中暑。）
犀角地黄汤（方见吐血。）
小柴胡汤（方见伤寒。）
解毒汤（方见伤寒。）
白虎汤（方见伤寒。）
小承气汤（即大黄、枳实，浓朴、水煎服。）
防风通圣散（方见中风。）
导赤散（即生地、木通、甘草、淡竹叶七个，水煎服。）
柴苓汤（即小柴胡汤合五苓。）
四君子汤（方见补益。）
四物汤（方见补益。）
理中汤（方见中寒。）
清毒饮（牛蒡子、防风、荆芥、甘草，水煎服。）
麻疹，是由于六腑和肠胃的热邪蒸腾于肺，同时伴有外感邪气和内伤因素共同作用所致。它的外观与痘疹相似，但内在病机实则不同。初期发热持续三天，出疹及胀期共三天，期间皮疹会出现“出而又没，没而又出”的现象，大约经历一个周期。病情较重者，全身皮肤紧绷肿胀，眼睛也会因肿胀而闭合。皮疹颜色有赤色、白色、微黄色等不同，但仍以红润鲜活为佳；最忌讳的是黑陷以及面目、胸腹部位皮疹稠密，咽喉部被包裹缠滞的情况，这些属于逆证。如果疹子发不出来且出现气喘，则预后不良，甚至致死。麻疹与大科瘾疹（荨麻疹类疾病）相似，又与发斑（斑疹）相似，如锦缎上的花纹，有空缺处，形状像云头一样。麻疹本身就像麻子一样遍布全身没有空缺，只是疏密程度不同罢了，有时还会夹杂斑、丹（丹毒）、疮一同发出。
初起时，症状表现为呵欠、发热、恶寒、咳嗽、喷嚏、流涕、头晕目眩，适宜使用升麻葛根汤加入紫苏、葱白来解肌发表。切忌大汗淋漓。对于斑疹不红的情况也适用此法，这是治疗麻疹和痘疹初起的良方。如果潮热严重，加入黄芩、黄连、地骨皮；出现胡言乱语，用辰砂六一散调服；咳嗽加重，加入麻黄、杏仁、麦冬、石膏；咳嗽剧烈，另用凉膈散加桔梗、地骨皮；腹泻适宜用四苓散；便血合用犀角地黄汤；呕吐、鼻出血加入炒山栀；小便不利色赤加入木通；寒热往来像疟疾一样，用小柴胡汤。
疹子已经发出，若出现烦躁、口渴，用解毒汤合白虎汤；气喘且大便闭结，用前胡枳壳汤加赤茯苓、大黄、甘草、五味子，水煎服用；大便闭结三四天，用小承气汤、防风通圣散；胡言乱语且尿闭，用导赤散；大便像米泔水一样，用四苓散加车前子、木通；胡言乱语如狂躁状，用解毒汤调服辰砂六一散；大便带血、小便也见血的，用犀角地黄汤合解毒汤；吐血、鼻出血，用解毒汤加炒山栀、童便；腹泻，用解毒汤合四苓散；气喘兼腹泻、小便涩痛，用柴苓汤；烦渴、呕吐、腹泻，用白虎汤加苍术、猪苓汤；热盛导致干呕，用解毒汤；伤食导致的呕吐，用四君子汤；夏季因暑气导致呕吐，用四苓散加人参。忌用豆蔻、木香、生姜、肉桂等热性药物。
麻疹病症在初起、已出、已没以及一切杂症中，与痘毒大同小异，但全程用药宜清凉。虽然麻疹喜清凉、痘疹爱温暖，但这并非固定不变的道常，虚证则补，实证则泻，这是医家的灵活治法。因此治疗麻疹也有血虚而用四物汤，气虚用四君子汤，天寒受冷则用温中、理中的药物，这是一时的权宜之计。
麻疹消退后，余热内攻，出现循衣摸床、胡言乱语、神志昏迷丧志的情况，预后不良，多致死。如果热势较轻，余毒未除，必先观察各种气色变化，虽然预防和治疗始终应以升麻葛根汤为主，或选用消毒饮、解毒汤，随症状选择。仍然忌食鱼腥、葱蒜等食物。
升麻葛根汤（方剂见痘疮章节。）
辰砂六一散（即益元散，方剂见中暑章节。）
凉膈散（方剂见火证章节。）
四苓散（即五苓散，方剂见中暑章节。）
犀角地黄汤（方剂见吐血章节。）
小柴胡汤（方剂见伤寒章节。）
解毒汤（方剂见伤寒章节。）
白虎汤（方剂见伤寒章节。）
小承气汤（即大黄、枳实、厚朴，水煎服用。）
防风通圣散（方剂见中风章节。）
导赤散（即生地、木通、甘草、淡竹叶七片，水煎服用。）
柴苓汤（即小柴胡汤合五苓散。）
四君子汤（方剂见补益章节。）
四物汤（方剂见补益章节。）
理中汤（方剂见中寒章节。）
清毒饮（牛蒡子、防风、荆芥、甘草，水煎服用。）
Measles is caused by the steaming of heat from the six fu organs and intestines/stomach into the lungs, combined with simultaneous external contraction and internal injury. Its appearance resembles that of smallpox (variola), but its internal pathology is fundamentally different. The initial fever lasts for three days, followed by a three-day period of eruption and distension. During this time, the rash may appear and disappear repeatedly, completing a cycle in approximately one day. In severe cases, the entire body becomes tense and swollen, and the eyes may be closed due to swelling. The rash color varies between red, white, and slightly yellow, but it should ideally be red and vibrant. The most unfavorable signs are black depression (blackening and sinking of the rash) and dense clustering on the face, eyes, chest, and abdomen, or when the throat is constricted and wrapped by the rash; these indicate adverse conditions. If the rash fails to erupt and is accompanied by asthma/wheezing, the prognosis is fatal. Measles resembles large-scale urticaria (hives-like diseases) and also resembles macular eruptions (macules/rashes), appearing like patterns on brocade with gaps, resembling cloud shapes. True measles presents as tiny spots covering the whole body without gaps, differing only in density. It may also occur concurrently with macules, erysipelas (erythema), and sores.
At the onset, symptoms include yawning, fever, aversion to cold, cough, sneezing, runny nose, and dizziness. It is appropriate to use Shengma Gegen Tang (Cimicifugae et Puerariae Decoction) added with Zisu (Perilla Leaf) and Congbai (Scallion White) to release the muscle layer. Profuse sweating must be strictly avoided. This formula is also suitable for non-red macular eruptions and is considered a divine prescription for the early stage of measles and smallpox. If tidal fever is severe, add Huangqin (Scutellaria Root), Lianzi (Coptis Rhizome), and Digupi (Groundcherry Bark); if delirious speech occurs, administer Chen Sha Liuyi San (Cinnabar Six-to-One Powder); for cough, add Mahuang (Ephedra Stem), Xingren (Apricot Seed), Maidong (Ophiopogon Tuber), and Shigao (Gypsum Fibrosum); for severe cough, separately use Liangge San (Cool the Chest Powder) added with Jiegeng (Platycodon Root) and Digupi; for diarrhea, Si Ling San (Four-Poria Powder) is suitable; for hematochezia, combine with Xijiao Dihuang Tang (Rhinoceros Horn and Rehmannia Decoction); for vomiting and epistaxis, add Chao Shanzhi (Stir-fried Gardenia Fruit); for dark and scanty urine, add Mutong (Akebia Stem); for chills and fever resembling malaria, use Xiao Chaihu Tang (Minor Bupleurum Decoction).
The early stage of measles closely resembles Taiyang disease (cold damage), distinguished only by facial redness and coldness of the middle finger.
If the rash has erupted and is accompanied by irritability and thirst, use Jiedu Tang (Detoxification Decoction) combined with Baihu Tang (White Tiger Decoction); for asthma and constipation, use Qianhu Zhike Tang (Peucedani and Aurantii Fructus Decoction) added with Chi Fuling (Red Poria), Dahuang (Rhubarb Root), Gancao (Licorice Root), and Wuwei Zi (Schisandra Berry), decocted in water; for constipation lasting three to four days, use Xiaochengqi Tang (Minor Order the Yang Decoction) or Fangfeng Tongsheng San (Saposhnikovia and Gentiana Powder); for delirium and urinary retention, use Daochi San (Guide Out the Red Powder); for stool resembling rice washings, use Si Ling San added with Cheqianzi (Plantago Seed) and Mutong; for delirious speech resembling mania, use Jiedu Tang mixed with Chen Sha Liuyi San; for blood in both stool and urine, combine Xijiao Dihuang Tang with Jiedu Tang; for hematemesis and epistaxis, use Jiedu Tang added with Chao Shanzhi and Tongbian (Child's Urine); for diarrhea, combine Jiedu Tang with Si Ling San; for asthma accompanied by diarrhea and dysuria, use Chai Ling Tang (Bupleurum and Poria Decoction); for irritability, thirst, vomiting, and diarrhea, use Baihu Tang added with Cangzhu (Atractylodes Rhizome) and Zhuling Tang (Polyporus Decoction); for dry heaving due to excessive heat, use Jiedu Tang; for vomiting due to food stagnation, use Sijunzi Tang (Four Gentlemen Decoction); for vomiting due to summerheat in summer, use Si Ling San added with Renshen (Ginseng Root). Avoid using hot herbs such as Doukou (Nutmeg), Muxiang (Costus Root), Jiang (Ginger), and Guizi (Cinnamon Twig).
In the early, erupted, resolved stages of measles, and in all miscellaneous syndromes, the pathology is largely similar to smallpox toxin, but the treatment throughout should favor cooling. Although measles favors cooling and smallpox favors warmth, this is not an immutable rule; deficiency requires tonification, excess requires purging, which constitutes the flexible practice of physicians. Therefore, treating measles may involve using Siwu Tang (Four Substances Decoction) for blood deficiency, Sijunzi Tang for qi deficiency, and warming/middle-regulating formulas like Lizhong Tang for cold injury in winter weather, as temporary expedients.
After the resolution of measles, residual heat attacks internally, leading to picking at bedclothes, delirious speech, and loss of spirit/consciousness, which indicates death. If the heat is mild and residual toxins remain, one must first observe various complexion changes. Prevention and treatment should primarily rely on Shengma Gegen Tang, or alternatively select Xiaodu Yin (Detoxifying Drink) or Jiedu Tang according to symptoms. Consumption of fish, seafood, scallions, and garlic should still be avoided.
Shengma Gegen Tang (Formula see Smallpox chapter.)
Chen Sha Liuyi San (i.e., Yiyuan San, Formula see Summerheat chapter.)
Liangge San (Formula see Fire Syndrome chapter.)
Si Ling San (i.e., Wuling San, Formula see Summerheat chapter.)
Xijiao Dihuang Tang (Formula see Hematemesis chapter.)
Xiao Chaihu Tang (Formula see Cold Damage chapter.)
Jiedu Tang (Formula see Cold Damage chapter.)
Baihu Tang (Formula see Cold Damage chapter.)
Xiaochengqi Tang (i.e., Dahuang, Zhishi, Houpo, decocted in water.)
Fangfeng Tongsheng San (Formula see Wind Stroke chapter.)
Daochi San (i.e., Shengdi, Mutong, Gancao, Danzhuye [Seven leaves], decocted in water.)
Chai Ling Tang (i.e., Xiao Chaihu Tang combined with Wuling San.)
Sijunzi Tang (Formula see Tonification chapter.)
Siwu Tang (Formula see Tonification chapter.)
Lizhong Tang (Formula see Middle Cold chapter.)
Qingdu Yin (Niubangzi, Fangfeng, Jingjie, Gancao, decocted in water.)