痘疹之由，因儿在胎，食母五脏血秽，伏于命门，或至天行时气，或惊骇跌扑，或饮食所伤，因而发之，状类伤
寒。其症面燥腮赤，目胞亦赤，呵欠顿闷，乍凉乍热，咳嗽嚏喷，足稍冷，耳冷尻冷，多睡睡惊，耳后有红丝赤脉，此
其候也。五脏各具一证，肝藏水 ，肺藏脓 ，心藏 ，脾藏疹，归肾变黑。盖以太阳起于右肾之下，煎熬左肾，足太
阳膀胱寒水夹脊上流，上头下额，逆手太阳，丙火不得传道，逆于面上，故显是诸症。盖壬癸寒水克丙丁热火故也。
凡疮疹初起，一发便出尽者必重。疮夹疹者，半轻半重。稀少者轻，里外微红者轻，外黑里赤者微重，外白里黑者太
重，疮端里黑点如针孔者势剧也。青干紫陷，睡昏汗出不止，烦躁热渴，腹胀啼喘，大小便不通者，困也。
痘疹正病，蒸热一日稍凉现 ，一日至三日足心齐，渐大如珠结成脓窠饱满，渐至苍蜡色。自初红 为始，计七日
当成靥结痂，此则言其大略也。人有虚实之不同，病有浅深之各异，脾胃充实，血气调和，皆根据期而愈。若调治失宜，
亏损脾胃；或寒暄失度，必致迁延。大抵情势既正，而无他症，不必用药，此先哲之格言也。郑氏云∶凡疮痘欲出，先
发热，轻者三日，次五日，远者不过七日，此约法也。一日太阳传膀胱，二日阳明传胃，三日少阳传胆，四日太阴传
脾，五日太阴传肾，六日厥阴传肝，七日还经，五脏六腑传遍，故七日而止也。又有因伤寒至七日以后，或已汗、或
未汗，或吐下后热不除，此毒瓦斯盛而未发，热毒入胃，发于皮肤。成 者，状如蚊虫所啮，赤者十生一死，黑者十死一
生。及有胃热发黄者，状如橘色，下利者死。又有成隐疹者，或白泡者，此皆伤寒热毒不除，多变此疾。故发 不可
用表汗药也。
痘疹的成因，是因为婴儿在母胎中摄入了母亲五脏的血秽之气，潜伏于命门；或者遇到时行疫病之气，或者受到惊吓、跌扑损伤，或者饮食不当受伤，从而引发疾病，症状表现类似于伤寒。其症状表现为面部干燥、两腮发红，眼睑也发红，频繁打哈欠且神情困顿，忽冷忽热，咳嗽打喷嚏，脚部稍凉，耳朵和尾骨部位发凉，嗜睡或睡中惊悸，耳后有红色血丝脉络，这是痘疹的征候。五脏各自对应一种证候：肝主水痘，肺主脓疱，心主斑疹，脾主疹点，若病邪归肾则变为黑痘。这是因为足太阳膀胱经起于右肾之下，煎熬左肾，足太阳膀胱寒水之气夹脊而上流，上至头部和下额，逆传入手太阳小肠经，导致丙火（小肠/心火）无法正常传导，逆冲于面部，因此显现出上述诸症。这是由于壬癸寒水克制丙丁热火所致。
凡是疮疹初起，一发出来就全部出齐的，病情必然严重。疮与疹夹杂出现的，病情半轻半重。出得稀少的为轻症，内外颜色微红的为轻症，外色黑内色赤的为轻微重症，外色白内色黑的为太重之症，疮顶内部有黑点如针孔状的，病情剧烈。出现青色干枯、紫色下陷，昏睡、汗出不止，烦躁、发热口渴，腹胀、啼哭喘息，大小便不通的，属于危困之症。
痘疹的正病过程，蒸热一天后稍凉即现出疹子，从第一天到第三天，足心同时出疹，逐渐增大如珠粒，结成脓窠并饱满，逐渐变为苍蜡色。从最初发红开始计算，七天应当结痂成靥，这说的是大概规律。人有虚实体质的不同，病有浅深程度的差异，如果脾胃充实，气血调和，都能按期痊愈。如果调治失当，亏损了脾胃；或者冷暖调节失度，必定导致病程迁延。大抵病情态势正常，而没有其他兼症，不必用药，这是先哲留下的格言。郑氏说：凡是疮痘欲出，先发热，轻者三天，次者五天，远者不超过七天，这是大概的法度。第一天病在太阳经传入膀胱，第二天阳明经传入胃，第三天少阳经传入胆，第四天太阴经传入脾，第五天太阴经传入肾，第六天厥阴经传入肝，第七天还经，五脏六腑传遍，所以七天而止。又有因伤寒至七日以后，或者已经发汗、或者未发汗，或者吐下之后热势不退，这是毒气旺盛而未发出，热毒入胃，发于皮肤。形成“成”字状（此处指某种特定形态的皮疹，原文可能有缺字或通假，依文意译为特定形态），形状像蚊虫叮咬，红色的十人中有九人生还，黑色的十人中有九人死亡。以及有因胃热发黄者，形状像橘子色，伴有腹泻的预后不良。又有形成隐疹的，或者有白色水泡的，这都是因为伤寒热毒未除，多变生此类疾病。因此，发痘疹不可使用解表发汗的药物。
The etiology of smallpox and chickenpox lies in the infant's ingestion of blood turbidity from the mother's five zang organs while in the womb, which remains latent in the Mingmen (Gate of Life); or it may be triggered by epidemic qi, fright, falls, dietary injuries, thereby manifesting with symptoms resembling Taiyang disease (Taiyang syndrome). The clinical manifestations include dry face and red cheeks, red eyelids, frequent yawning with lethargy, alternating chills and fever, coughing and sneezing, cool feet, cool ears and coccyx, excessive sleepiness or startle during sleep, and red vascular patterns behind the ears. These are the signs of the disease. Each of the five zang organs corresponds to a specific manifestation: the Liver governs water blisters, the Lungs govern pus-filled pustules, the Heart governs macules, the Spleen governs papules, and if the pathogen returns to the Kidneys, it turns black. This is because the Foot-Taiyang Bladder meridian originates below the right kidney, scalding the left kidney; the cold water of the Foot-Taiyang Bladder flows up along the spine, reaching the head and forehead, and reversely transmits to the Hand-Taiyang Small Intestine meridian. Consequently, Bing Fire (Small Intestine/Heart fire) cannot transmit properly, reversing upward to the face, thus producing these symptoms. This occurs due to the restriction of Bing-Ding Fire by Ren-Gui Water.
Generally, if all lesions erupt simultaneously at the onset, the condition is severe. If sores and rashes appear together, the severity is moderate. Scarcity indicates mildness; slight redness inside and out indicates mildness; black exterior with red interior indicates slightly severe; white exterior with black interior indicates extremely severe; and black dots like needle holes at the lesion apex indicate critical intensity. Cyanosis with dryness, purple depression, coma, incessant sweating, irritability, fever, thirst, abdominal distension, crying with wheezing, and obstruction of urination and defecation indicate a critical state.
In the typical course of smallpox/chickenpox, there is steaming fever for one day, followed by slight cooling and eruption. By the third day, eruptions appear on the soles of the feet. They gradually enlarge like pearls, forming full, pus-filled pits, and eventually turn into a grayish-wax color. Counting from the initial redness, crusting should occur by the seventh day; this describes the general rule. Individuals vary in deficiency and excess, and diseases differ in depth. If the Spleen and Stomach are robust and Qi and Blood are harmonious, recovery occurs according to schedule. However, improper treatment damaging the Spleen and Stomach, or inappropriate exposure to cold and heat, will inevitably lead to protracted illness. Generally, if the disease pattern is standard without other complications, medication is unnecessary; this is an adage of the sages. Zheng stated: For impending sores or smallpox, fever precedes eruption. Mild cases take three days, moderate five, and severe no more than seven; this is a rough guideline. On the first day, the pathogen is in the Taiyang meridian transmitting to the Bladder; on the second day, Yangming to the Stomach; on the third day, Shaoyang to the Gallbladder; on the fourth day, Taiyin to the Spleen; on the fifth day, Taiyin to the Kidney; on the sixth day, Jueyin to the Liver; on the seventh day, it returns to the channel. After traversing the five zang and six fu organs, the cycle stops at seven days. Additionally, in cases of Shanghan (Cold Damage) persisting beyond seven days, whether after sweating or not, or after vomiting/purging where heat persists, this indicates abundant toxic qi that has not erupted. Heat toxin enters the Stomach and manifests on the skin. Lesions resembling mosquito bites: red ones have nine survivors out of ten; black ones have only one survivor out of ten. Jaundice due to Stomach heat, resembling orange color, accompanied by diarrhea, indicates death. Eruptions presenting as hidden rashes or white blisters also result from uneliminated heat toxin from Shanghan, often transforming into such conditions. Therefore, diaphoretic (sweat-inducing) medicines must not be used when treating eruptive diseases.