麻虽胎毒，多带时行，气候寒温非令，男女传染而成。其发也，与痘相似；其变也，比痘匪轻。愚夫愚妇
每视为泛常，若死若生总归于天命。不知毒起于胃，热流于心。始终之变，肾则无证；脏腑之伤，肺则尤甚。闭
户问途，何若出门寻径；扬汤止沸，不如去火抽薪。
初时发热，俨似伤寒。目出泪而不止，鼻流涕而不干。咳嗽太急，烦躁难安。以火照之，隐隐皮肤之下；以
手抹之，亭亭肌肉之间。其形若疥，其色若丹；随出随没，乍隐乍现。根窠若肿兮，麻而兼瘾；皮肤若赤兮，
麻以夹斑。似锦而明兮，十有九吉；如煤而黑兮，百无一痊。
麻毒最重，治法不同。微汗常出，热势越而不留；清便自调，毒瓦斯行而无壅。腠理拂郁兮，即当发散；肠
胃秘结兮，急与疏通。苟视大而若细，恐变吉而为凶。故衄血不必忧，邪从衄解；利血不必止，毒以痢松。所
喜者身中清凉，可畏者咽中肿痛。饮水不休，法在生津养血；饮食若减，方须清胃和中。
又如出之太迟，发表为贵；出之过甚，解毒堪宜。毋伐天和，常视岁气。寒威凛凛，毒势郁而不行；火热
炎炎，邪气乘而作疠。或施温补，勿助其邪；若用寒凉，休犯其胃。制其过但取其平，诛其暴必欲其正。远寒远
热，阴阳之胜负不齐；责实责虚，人禀之强弱或异。
麻疹既出，将息尤难。坐卧欲暖，饮食宜淡。风寒若袭兮，为肿为热；咸酸不禁兮，为咳为喘。异气纵感，
变证宜参。便多脓血兮，仓廪血热；咳多涎沫兮，华盖伤寒。口烂唇裂，心火未退；皮焦发槁，荣卫将枯。苟
不详于临证，何以见其折肱？
麻疹虽然源于胎毒，但多夹杂时行疫气，因气候寒温失常，男女之间相互传染而发病。其发作时的表现，与痘疹相似；但其病情变化，比痘疹更为严重。愚昧的百姓往往将其视为平常疾病，无论生死都归结为天命。却不知道毒邪起于胃，热邪流注于心。在病程始终的变化中，肾脏通常没有明显证候；而在脏腑损伤方面，肺部尤为严重。这就好比关着门问路，不如出门寻找路径；用扬汤止沸的方法，不如抽去柴火以除根。
初期发热，很像伤寒。眼睛流泪不止，鼻涕流出不干。咳嗽剧烈，烦躁不安难以平静。用火光照看，皮疹隐隐约约出现在皮肤之下；用手抚摸，皮疹亭亭玉立地隆起在肌肉之间。其形态像疥疮，颜色像丹砂；随着出疹随即消退，时而隐藏时而显现。如果根部肿胀，则是麻兼有瘾疹；如果皮肤发红，则是麻夹带斑疹。如果皮疹像锦缎一样鲜明，十中有九预后良好；如果像煤炭一样黑黯，百人中难有一人痊愈。
麻毒最为沉重，治疗方法也各不相同。微微出汗，热势就会散发而不滞留；大小便自然调和，毒邪就能运行而没有壅滞。如果腠理闭塞郁结，就应当发散透疹；如果肠胃秘结不通，就急需疏通导滞。如果诊脉看似盛大实则细微，恐怕会将吉兆变为凶险。所以鼻出血不必担忧，因为邪气随血而解；下痢脓血不必强行止住，因为毒邪随痢而减轻。令人欣慰的是身体清凉，值得畏惧的是咽喉肿痛。饮水不停，治法在于生津养血；饮食减少，方药须清胃和中。
又比如出疹太迟，发表透疹最为重要；出疹过甚，解毒清热适宜。不要破坏人体的和谐之气，要常观察当年的岁气。寒气凛冽，毒势郁结而不能外发；火热炎炎，邪气乘虚而入导致疫病流行。或者施以温补，不要助长邪气；如果使用寒凉药物，不要伤害胃气。制约过偏只需取其中平，诛伐暴烈必欲使其中正。远离寒冷和过热，因为阴阳胜负的情况不同；责求实证或虚证，因为人的禀赋强弱各异。
麻疹既然已经发出，调护尤其困难。坐卧想要温暖，饮食宜清淡。如果风寒侵袭，会导致肿胀发热；咸味酸味食物不能耐受，会导致咳嗽气喘。即使感受了异气（杂病之气），变证也应参考辨证。大便多脓血，是脾胃血热；咳嗽多涎沫，是肺脏受寒。口舌糜烂嘴唇干裂，说明心火未退；皮肤焦枯头发干枯，说明营卫气血将枯竭。如果不详细考察临证情况，怎么能体现高超的医术呢？
Although measles originates from fetal toxin (Tai Du, inherent pathogenic factors), it often carries epidemic qi (Shi Xing, seasonal pathogenic factors). It is caused by abnormal climatic changes of cold and warmth, leading to transmission between males and females. Its onset resembles smallpox (Dou Zhen); however, its variations are more severe than those of smallpox. Ignorant people often regard it as an ordinary disease, attributing life or death to fate. They do not know that the toxin arises from the Stomach (Wei) and heat flows into the Heart (Xin). Throughout the course of the disease, there are no specific symptoms in the Kidney (Shen); among the zang-fu organs, the Lung (Fei) suffers the most damage. Asking for directions with doors closed is inferior to going out to find a path; stopping boiling water by stirring is inferior to removing the firewood from under the pot.
In the initial stage, fever occurs, resembling Cold Damage (Shang Han). Tears flow continuously from the eyes, and nasal discharge does not dry up. Coughing is severe, accompanied by irritability and restlessness. When illuminated by fire, the rash appears faintly beneath the skin; when touched by hand, it stands out clearly within the muscles. Its shape resembles scabies, and its color resembles cinnabar; it appears and disappears intermittently. If the base is swollen, it is measles combined with urticaria (Yin Zhen); if the skin is red, it is measles accompanied by macules/papules (Ban). If the rash is bright like brocade, nine out of ten cases are auspicious; if it is black like coal, hardly one in a hundred recovers.
The measles toxin is heaviest, so the treatment methods differ. Mild sweating allows the heat to dissipate without lingering; normal bowel movements ensure the toxin circulates without obstruction. If the pores are closed and stagnant, dispersing and venting methods should be used immediately; if the intestines and stomach are constipated, urgent unblocking and purging are required. If the pulse appears large but feels thin inside, one must fear that auspicious signs may turn into ominous ones. Therefore, epistaxis (nosebleed) need not cause worry, as the pathogen resolves through bleeding; dysentery with blood need not be stopped forcibly, as the toxin is relieved through purgation. What is pleasing is the coolness of the body; what is feared is swelling and pain in the throat. Constant thirst requires methods to generate fluids and nourish blood; reduced appetite necessitates formulas to clear the stomach and harmonize the middle jiao.
Furthermore, if eruption is too delayed, releasing the exterior is paramount; if eruption is excessive, clearing toxicity is appropriate. Do not disrupt the harmony of Heaven and Human (Tian He), but always observe the annual climate. If the cold is biting, the toxin becomes stagnant and fails to emerge; if the heat is blazing, the pathogen takes advantage to cause epidemics. One may apply warming and tonifying methods, but do not assist the pathogen; one may use cooling and purging methods, but do not injure the stomach. Moderating excess aims only at balance; suppressing violence aims at restoring righteousness. Avoiding both cold and heat depends on the imbalance of yin and yang; addressing excess or deficiency depends on the individual's constitutional strength.
Once measles have erupted, nursing care is particularly difficult. Sitting and lying should be kept warm, and diet should be bland. If wind-cold invades, it causes swelling and heat; intolerance to salty or sour foods leads to cough and asthma. Even if affected by other pathogens, variable syndromes should be considered. Frequent pus and blood in stool indicates heat in the spleen and stomach blood; copious phlegm and foam in cough indicates cold damaging the lung (Hua Gai, metaphor for lungs). Mouth ulcers and cracked lips indicate that heart fire has not subsided; scorched skin and withered hair indicate that nutritive (Ying) and defensive (Wei) qi are about to dry up. Without detailed examination during clinical practice, how can one demonstrate mastery of medicine?