阳明燥令司天之年。或秋冬之交。天久不雨。燥气盛行。邪客于肺。伏而化火。至初
春雨水骤至。春寒外加。（夏至后发者更重）少阳相火。不能遂其条达之机。遂挟少阴君火。循经
络而上与所伏之燥火。互相冲激。猝乘咽喉清窍而出。或发白块。或白点。名曰白
喉。互相传染。大人易治。小儿难治。
时疫喉症。不外外感六淫为病。六淫者即经所谓风寒燥湿暑火六气是也。历考古人
喉科方论。言风火者固多。言寒湿者亦颇不乏。独未有专言燥气为病者。盖内经脱
秋伤于燥一条。后人遂有燥气不为病之说。至沈自南喻嘉言始各有所得。各出方
论。沈氏以化气为湿为主。故立方偏于苦辛微温。喻氏以复气为火为主。故立方偏
于辛凉甘寒。赖吴鞠通氏有燥气为病。轻则为燥。重则为寒。化气为湿。复气为火
数语。而燥气发病之理始着。后之治燥气者。亦有门迳可入。（欲治白喉者非先读沈喻吴三先生之书
恐终无从下手）此症之发。必于燥气盛行之年。且见症经脉传变治法。无一不与燥火二字吻合。故
知病属燥气无疑。（详观后辨自明）唯间多挟少阳相火少阴君火而发。不得不兼治耳。郑氏梅
涧虽言此症或遇燥气流行而发。而支离庞杂。尚非真能探及源头者。至张氏漫言火
热。（喉症属火热者比比皆是）耐修氏言肺之灼。由于胃之热。胃之热。实由于肠之寒。模糊影响。
全无确见。更不足辨矣。大人小儿治法本同。何分难易。实以小儿在五六龄以内
者。未识人事。看验服药。处处不能如法。故治之较难也。
在阳明燥气主司天时的年份，或者秋冬交替之际，如果天空长久不下雨，燥气就会盛行。邪气侵犯肺部，潜伏下来并化为火邪。到了初春雨水突然增多时，外界的春寒侵袭人体。（如果在夏至之后发病，病情会更严重）少阳相火无法顺利发挥其条达舒展的功能，于是挟持着少阴君火，沿着经络向上运行，与体内潜伏的燥火相互冲激，突然从咽喉这一清窍处发作出来。有的表现为白色的斑块，有的表现为白色的斑点，这种病叫做白喉，具有传染性。成年人患病容易治疗，小儿患病则难以治疗。
这类时疫引起的喉部病症，不外乎是外感六淫邪气所致。所谓六淫，就是经典中所说的风、寒、燥、湿、暑、火这六种气候异常变化。回顾古代医家关于喉科的方论，谈论风火致病的固然很多，谈论寒湿致病的也不少，唯独没有专门论述燥气致病的著作。这是因为《黄帝内经》中缺失了“秋伤于燥”这一条文，后人便产生了燥气不会致病的说法。直到沈自南和喻嘉言两位医家才开始各有心得，各自提出了方论。沈氏认为化气以湿为主，所以他的处方偏向于苦辛微温；喻氏认为复气以火为主，所以他的处方偏向于辛凉甘寒。幸亏吴鞠通先生有“燥气致病，轻则为燥，重则为寒，化气为湿，复气为火”这几句话，使得燥气致病的原理才变得显著。后来治疗燥气疾病的医者，也有了门径可以遵循。（想要治疗白喉的人，如果不先阅读沈、喻、吴三位先生的著作，恐怕最终无从下手）。这种病症的发生，必然是在燥气盛行的年份，而且其症状表现、经脉传变以及治疗方法，没有哪一点不与“燥火”这两个字相吻合。因此知道此病属于燥气无疑。（详细观察后面的辨析自然明白）。只是中间多夹杂少阳相火和少阴君火而发作，不得不兼治罢了。郑梅涧虽然提到此症有时遇到燥气流行而发作，但他的论述支离破碎、庞杂混乱，还不是真正能探及病源的人。至于张氏漫谈火热（喉症属于火热的比比皆是），耐修氏说肺部的灼热是由于胃的热，而胃的热实际上是由于肠的寒，这些观点模糊不清，毫无确切见解，更不值得辩论了。大人和小儿的治疗原则本来相同，为何区分难易？实际上是因为五岁以内的小儿，不懂人事，诊察验证和服药护理，处处都不能合乎规范，所以治疗起来比较困难。
In years when the Yangming dryness governs the heavenly qi, or during the transition between autumn and winter, if there has been no rain for a long time, dryness qi will prevail. Pathogenic factors invade the Lung, lie dormant, and transform into fire. When early spring arrives with sudden rains, external spring cold attacks the body. (Cases occurring after the Summer Solstice are more severe.) The Shaoyang ministerial fire cannot smoothly execute its mechanism of free flow and expansion. Consequently, it carries the Shaoyin sovereign fire, moving upward along the meridians to clash with the latent dryness-fire, suddenly erupting through the clear orifices of the throat. It may manifest as white patches or white spots, known as Baihou (Diphtheria/White Throat). It is contagious. Treatment in adults is relatively easy, while treatment in children is difficult.
Epizootic throat disorders are not beyond the pathology caused by the exogenous Six Excesses (Wind, Cold, Dryness, Dampness, Summerheat, Fire). The Six Excesses refer to the six abnormal climatic conditions mentioned in classics: Wind, Cold, Dryness, Dampness, Summerheat, and Fire. Reviewing ancient medical theories on throat diseases, those discussing Wind-Fire are numerous, and those discussing Cold-Dampness are also quite common. However, there are none that specifically discuss disease caused by Dryness Qi. This is because the *Huangdi Neijing* (Yellow Emperor's Inner Canon) lacks the section on "Autumn injury by Dryness," leading later generations to believe that Dryness Qi does not cause disease. It was not until Shen Zinan and Yu Jiayan that each gained unique insights and presented their own formulas and theories. Shen believed that the transformational qi is primarily dampness, so his prescriptions leaned towards bitter, acrid, and slightly warm herbs. Yu believed that the returning qi is primarily fire, so his prescriptions leaned towards acrid-cool and sweet-cold herbs. Fortunately, Wu Jutong provided the statement that "Dryness Qi causes disease; light cases present as Dryness, heavy cases as Cold; the transformational qi is Dampness, and the returning qi is Fire." Thus, the principles of Dryness Qi causing disease became clear. Later practitioners treating Dryness Qi had pathways to follow. (Those wishing to treat Baihou must first read the works of Masters Shen, Yu, and Wu, otherwise they will likely find no starting point). The onset of this condition must occur in years where Dryness Qi prevails. Moreover, its symptoms, meridian transmission, and treatment methods all align perfectly with the concept of Dryness-Fire. Therefore, it is certain that the disease belongs to Dryness Qi. (Detailed observation of subsequent analyses will make this clear). However, it often occurs accompanied by Shaoyang Ministerial Fire and Shaoyin Sovereign Fire, necessitating combined treatment. Zheng Meijian did mention that this condition sometimes arises during the prevalence of Dryness Qi, but his exposition was fragmented and chaotic, failing to truly probe the source of the disease. As for Zhang's vague discussion of Fire-Heat (cases of throat disorders attributed to Fire-Heat are ubiquitous), and Naixiu's assertion that lung burning is due to stomach heat, and stomach heat is actually due to intestinal cold, these views are vague and insubstantial, lacking definite insight, and thus not worth debating. The treatment principles for adults and children are fundamentally the same; why distinguish between ease and difficulty? In reality, for children under five years old, who do not yet understand human affairs, examination, verification, and medication administration cannot be performed according to proper standards everywhere, making treatment comparatively difficult.