麻疹出时非一端，其中轻重要详参，气血和平轻而易，表裹交杂重则难。
[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。
%
疹宣发表透为先，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，便毒尽达于肌表，
若过用寒凉，冰伏毒热，则必不能出透，多致毒气内攻，喘闷而毙，
至若已出透者，又当用清利之品，便内无余热，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，表里无邪毒气松，若兼风寒食滞热，隐伏不出变丛生，
宣毒发表为主剂，随证加味莫乱从。
[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，毒气松动，则易出而易透，
若兼风寒食热诸证，其热必壮盛，毒气郁闭，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 牛蒡炒研 加引芫荽水煎服。
食滞加南山查 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。
%
The manifestation of measles eruption is not uniform; one must carefully distinguish between mild and severe cases. When Qi and Blood are harmonious, the condition is mild and easy to treat; when exterior and interior pathogenic factors are intermingled, the condition is severe and difficult to cure.
[Note]
Measles eruptions vary in severity, requiring detailed examination at the time of onset.
If a patient's Qi and Blood are harmonious and they have no underlying diseases, even if infected by seasonal pathogens, their healthy Qi can control the pathogen.
Thus, fever is mild with slight sweating, spirit is clear, and bowel and bladder functions are regular.
When spots appear, they emerge thoroughly and fade naturally, neither too fast nor too slow, indicating a mild and easily treatable case.
However, if a patient has pre-existing cold-wind or food stagnation, with exterior-interior pathogenic complexity, upon exposure to pathogenic Yang fire-heat energy,
internal and external pathogens erupt simultaneously, and healthy Qi fails to control the pathogen. This inevitably leads to high fever without sweating, restlessness, thirst, clouded spirit, constipation, and dysuria.
The spots fail to emerge thoroughly and dissipate, or recede too hastily, indicating a severe and difficult-to-treat case.
The primary principle for treating measles is to promote eruption and transparency; it is most taboo to use excessive cold-cooling herbs that trap toxins internally. After eruption, clearing and purging methods should be used to eliminate residual heat; after resolution, nourishing Yin and blood ensures recovery.
[Note]
For measles to erupt successfully, thoroughness is essential. Initially, methods to release the exterior should be employed so that toxins reach the muscle surface completely.
Overuse of cold-cooling herbs may cause ice-like entrapment of toxin-heat, preventing thorough eruption and often leading to internal attack of toxins, resulting in wheezing, chest oppression, and death.
For cases where eruption is already complete, clearing and purging agents should be used to ensure no residual heat remains, thereby avoiding 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, treatment should focus primarily on nourishing blood to ensure safety.
This constitutes the fundamental principles for treating measles from start to finish. Regarding flexible adjustments during clinical practice, physicians must rely on spiritual insight and discernment.
Mild fever precedes the eruption of measles, indicating no exterior-interior pathogens and loose toxin qi. If accompanied by cold-wind or food stagnation causing heat, the toxin remains latent and fails to erupt, leading to various complications.
Treatment should prioritize Xuan Du Fa Biao Tang (Toxin-Releasing Exterior-Expelling Decoction), with modifications based on symptoms, avoiding arbitrary adherence to other protocols.
[Note]
In measles, eruption requires heat; thus, body temperature rises first when eruption is imminent.
Without exterior-interior pathogens, fever is mild, toxin qi loosens, making eruption and transparency easy.
With concurrent cold-wind, food stagnation, or heat syndromes, fever becomes intense, toxin qi becomes depressed and closed, making eruption and transparency difficult.
Treatment employs Xuan Du Fa Biao Tang (Toxin-Releasing Exterior-Expelling Decoction). For complex syndromes, modify this formula according to specific symptoms.
(Xuan Du Fa Biao Tang [Toxin-Releasing Exterior-Expelling Decoction]): Shengma (Cimicifugae Rhizoma), Gegen (Puerariae Lobatae Radix), Qianhu (Peucedani Radix), Jiegeng (Platycodonis Radix), Zhike (Aurantii Fructus, stir-fried with bran), Jingjie (Schizonepetae Spica), Fangfeng (Saposhnikoviae Radix), Boheye (Menthae Haplocalycis Folium), Mutong (Akebiae Caulis), Lianqiao (Forsythiae Fructus, heart removed), Niubangzi (Arctii Fructus, fried and ground). Add Yuanxi (Coriandri Fructus) as a guiding herb; decoct in water and take orally.
Add Nanshan Zha (Crataegi Fructus) for food stagnation.
Add Huangqin (Scutellariae Radix) for internal heat.
(Decoction Verse)
For latent measles, use Xuan Du Fa Biao Tang;
Contains Shengma, Gegen, Qianhu, Jiegeng, Zhike, Jingjie, Fangfeng,
Bohe, Mutong, Lianqiao, Niubang, Dazhuye, Gancao;
Guide with Yuanxi, decoct in water and taste.