麻疹出时非一端，其中轻重要详参。气血和平轻而易，表里交杂重则难。
注∶麻疹出时有轻重之分，临时须要详察。若气血和平，素无他病者，虽感时气而正能制邪，故发热和
缓，微微汗出，神气清爽，二便调匀。见点则透彻散没，不疾不徐，为轻而易治者也。若素有风寒食滞，表里交
杂，一触邪阳火旺之气，内外合发，而正不能制邪，必大热无汗，烦躁口渴，神气不清，便闭尿涩。见点不能透彻，收
散或太紧速，则为重而难治者也。
疹宜发表透为先，最忌寒凉毒内含，已出清利无余热，没后伤阴养血痊。
注∶凡麻疹出贵透彻，宜先用表发，使毒尽达于肌表。若过用寒凉冰伏毒热，则必不能
出透，多致毒瓦斯内攻，喘闷而毙至。若已出透者，又当用清利之品，使内无余热，以免疹后
诸证。且麻疹属阳热，甚则阴分受伤，血为所耗，故没后须以养血为主，可保万全。此首尾
治疹之大法，至于临时权变，惟神而明之而已。
欲出麻疹身微热，表里无邪毒瓦斯松。若兼风寒食滞热，隐伏不出变丛生。宣毒发表为主剂，随证加减莫乱从。
注∶麻疹一证非热不出，故欲出时身先热也。表里无邪者热必和缓，毒瓦斯松动则易出而易透。若兼风寒食热
诸证，其热必壮盛，毒瓦斯郁闭则难出而难透。治以宣毒发表汤，其间或有交杂之证，亦照本方随证加减治之。
宣毒发表汤
升麻 葛根 前胡 桔梗 枳壳（麸炒） 荆芥 防风 薄荷叶 木通 连翘（去心） 牛蒡子（炒研） 淡
竹叶（即鲜竹叶） 生甘草
引加芫荽水煎服。凡服荆芥忌食鱼腥。
感寒邪者加麻黄，夏月勿用。
食滞加南山楂。
内热加黄芩。
方歌∶疹伏宣毒发表汤，升葛前桔枳荆防，薄通翘蒡淡竹草，引加芫荽水煎尝。
麻疹发作时的病情并非只有一种情况，其中轻症和重症需要详细辨别。气血调和则病情轻且容易治疗，表里邪气交杂则病情重且难以治愈。
注：麻疹发出时有轻症和重症的区别，临证时必须仔细诊察。如果患者气血平和，平时没有其他疾病，虽然感受了时行疫气，但正气能够制约邪气，所以发热缓和，微微出汗，精神清爽，大小便正常。皮疹显现时透发透彻、消散均匀，不快不慢，属于轻症且容易治疗的情况。如果患者平素有风寒或食积停滞，导致表里邪气交杂，一旦接触到邪热亢盛之气，内外合病而发，正气不能制约邪气，必然出现高热无汗、烦躁口渴、神志不清、大便闭塞、小便涩痛等症状。皮疹显现时不能透发透彻，消退收敛要么太紧促要么太迅速，这就属于重症且难以治疗的情况。
治疗麻疹应以发表透疹为优先原则，最忌讳使用寒凉药物导致毒邪内陷。皮疹已经出齐后，需用清热利湿之法清除余热；皮疹消退之后，需通过养血来促进康复。
注：凡是麻疹发出，贵在透发彻底，应当先用发表的方法，使毒邪完全达于肌表。如果过度使用寒凉药物，会导致冰伏毒热，必然不能透发出来，多导致毒瓦斯内攻，引起喘闷甚至死亡。如果皮疹已经透发，又应当使用清利的药物，使体内没有余热，以免发生疹后的各种并发症。而且麻疹属于阳热之证，严重时阴分会受伤，血液被耗损，所以在皮疹消退后必须以养血为主，这样可以保证万无一失。这是治疗麻疹从头到尾的大法，至于临证时的灵活变通，只能靠医者心领神会、明察秋毫罢了。
想要发出的麻疹身体仅有微热，说明表里没有邪气，毒瓦斯松动。如果兼有风寒、食滞和热邪，疹子就会隐伏不出，从而产生各种变证。治疗以宣毒发表汤为主要方剂，根据症状加减用药，不要随意更改。
注：麻疹这一病症，不是热势起来就不会发出，所以在欲出之时身体先发热。表里没有邪气的，热势必然缓和，毒瓦斯松动就容易发出且透发彻底。如果兼有风寒、食积、热邪等各种证候，热势必然壮盛，毒瓦斯郁闭就难发出且难透发。治疗使用宣毒发表汤，其间如果有夹杂的其他证候，也按照本方随证加减治疗。
宣毒发表汤
升麻、葛根、前胡、桔梗、枳壳（麸炒）、荆芥、防风、薄荷叶、木通、连翘（去心）、牛蒡子（炒研）、淡竹叶（即鲜竹叶）、生甘草。
煎服时加入芫荽作为药引，用水煎服。凡服用含有荆芥的方剂，忌食鱼腥食物。
感受寒邪者加麻黄，夏季不要用。
食积停滞者加南山楂。
内热盛者加黄芩。
The manifestation of measles is not uniform; its severity must be carefully differentiated. When Qi and Blood are harmonious, the condition is mild and easy to treat; when exterior and interior pathogens intermingle, the condition is severe and difficult to cure.
Note: Measles eruptions vary in severity and require careful examination at the time of presentation. If a patient has harmonious Qi and Blood and no underlying diseases, even if they contract seasonal epidemic pathogens, their righteous Qi can control the pathogenic factors. Thus, fever will be mild with slight sweating, mental clarity will be maintained, and bowel and bladder functions will be regular. The rash spots will appear thoroughly and dissipate evenly, neither too fast nor too slow, indicating a mild and easily treatable case. Conversely, if a patient has pre-existing cold-wind or food stagnation leading to an intermingling of exterior and interior pathogens, upon exposure to intense pathogenic heat, internal and external factors combine to trigger the disease. Righteous Qi fails to control the pathogens, resulting in high fever without sweating, irritability, thirst, clouded consciousness, constipation, and dysuria. The rash spots fail to erupt thoroughly, and their resolution may be either too abrupt or too delayed, indicating a severe and difficult-to-treat case.
The treatment of measles prioritizes releasing the exterior and promoting eruption; it is most contraindicated to use cold-cooling herbs that trap toxins internally. Once the rash has fully erupted, clearing heat and promoting diuresis removes residual heat; after the rash subsides, nourishing blood ensures recovery.
Note: For measles eruptions, thoroughness is paramount. Initially, methods to release the exterior should be used to ensure toxins reach the skin surface completely. Overuse of cold-cooling herbs may cause "ice-like" trapping of toxin-heat, preventing eruption and often leading to internal attack by toxic vapors, causing wheezing, chest oppression, and death. If the rash has already erupted thoroughly, clearing and draining agents should be employed to eliminate residual internal heat, thereby preventing post-measles complications. Since measles belongs to yang-heat patterns, severe cases may injure the Yin aspect and consume blood. Therefore, after the rash subsides, the primary treatment should focus on nourishing blood to ensure complete safety. This constitutes the fundamental principles for treating measles from onset to resolution. Regarding flexible adjustments during clinical practice, these depend on the physician's intuitive understanding and discernment.
When measles are about to erupt, the body exhibits only slight heat, indicating no exterior-interior pathogens and loose toxic vapors. If accompanied by cold-wind, food stagnation, and heat, the rash remains hidden and does not erupt, giving rise to various complications. The main formula is Xuan Du Fa Biao Tang (Toxin-Releasing Exterior-Release Decoction), with modifications based on symptoms; do not deviate arbitrarily.
Note: Measles do not erupt unless there is sufficient heat. Hence, slight fever precedes eruption. Without exterior-interior pathogens, the heat is mild, and loose toxic vapors facilitate easy eruption and penetration. With concurrent cold-wind, food stagnation, or heat, the fever becomes vigorous, and trapped toxic vapors hinder eruption and penetration. Treatment utilizes Xuan Du Fa Biao Tang (Toxin-Releasing Exterior-Release Decoction). If mixed syndromes exist, modify this base formula according to specific symptoms.
Xuan Du Fa Biao Tang (Toxin-Releasing Exterior-Release Decoction)
Shengma (Cimicifugae Rhizoma), Gegen (Puerariae Lobatae Radix), Qianhu (Peucedani Radix), Jiegeng (Platycodonis Radix), Zhike (Aurantii Fructus Immaturus, bran-fried), Jingjie (Schizonepetae Herba), Fangfeng (Saposhnikoviae Radix), Boheye (Menthae Haplocalycis Herba), Mutong (Akebiae Caulis), Lianqiao (Forsythiae Fructum, heart removed), Niubangzi (Arctii Fructum, fried and crushed), Danzhuyeh (Lophatheri Herba, i.e., fresh bamboo leaves), Sheng Gancao (Glycyrrhizae Radix et Rhizoma).
Add Yuanxi (Coriandri Fructus) as a guide drug, decoct with water. Avoid fishy-smelling foods when taking formulas containing Jingjie.
For cold-pathogen invasion, add Mahuang (Ephedrae Herba); avoid in summer.
For food stagnation, add Nanshan Zha (Crataegi Fructus).
For internal heat, add Huangqin (Scutellariae Radix).
Formula Verse:
Measles latent, Xuan Du Fa Biao Tang serves best,
Shengma, Gegen, Qianhu, Jiegeng, Zhike, Jingjie, Fangfeng rest.
Bohe, Mutong, Lianqiao, Niubangzi, Danzhu Ye, Gancao blend,
With Yuanxi as guide, decoct in water, take and mend.