夫痘疹之发也。身热和缓，达于外者必轻，闷乱烦躁，郁于内者必重，势之自然
也。故颜色贵润泽而嫌昏暗；贵光彩而嫌枯涩；贵淡红而嫌黑滞∶贵圆净而嫌破碎；贵
高耸而嫌平塌；贵稀疏而嫌稠密；皮贵结实而嫌虚薄。根窠收紧痘分阴阳，见点活动，
切忌浮肿，出要参差，血宜归附，耳后项颈心胸，少于他处为佳，眉棱两颧，额前光润
不滞为妙。若一发便出尽者，必重也。疮夹疹者，半轻半重也。出而稀少，里外微红
者，轻也。外黑里赤者，微重也。外白里黑者，太重也。疮端黑点，如针孔者，热剧而
势极也。青干紫陷，昏睡汗出烦燥热渴，腹胀啼喘，大小便秘者，困也。更凡痘色光润
红活者，气血和而旺也。惨暗者，气血衰也。气旺而血得其令，气衰而血被其囚，血
非气则毒不收，气非血则毒不化，信乎？痘毒必气血而后可以始终其功，然色之红者，
毒始出也。白者，毒未解也。黄者，毒将解也。黄腻者，毒尽解也。灰白者，血衰而气
滞也。焦褐者，气血枯也。焦紫者，枭淫邪毒炽结也。黑者，毒滞而血干也。红变白，
白变黄者，生。红变紫，紫变黑者，死之兆也。又有血与其毒相搏，抬成虚壳，虽见圆
满，实则空壳虚泡而色枯白者。又有气血皆离，而邪之火浮游，是以虽见红晕犹存，然
气虚不能续，血虚不能化，是以渐变干枯而萎者，并宜详别，毋轻视也。
痘疹发作时，如果身体发热且热度缓和、向外透发的，病情必然较轻；如果内心烦闷混乱、烦躁不安、邪气郁结在体内的，病情必然较重，这是势态发展的自然规律。因此，痘疹的颜色以滋润光泽为贵，忌讳昏暗无光；以光彩明亮为贵，忌讳干枯涩滞；以淡红色为贵，忌讳黑色瘀滞；以形状圆润洁净为贵，忌讳破碎不全；以隆起高耸为贵，忌讳平坦塌陷；以分布稀疏为贵，忌讳稠密拥挤；皮肤以结实饱满为贵，忌讳虚浮薄弱。痘根的窠臼收紧，可以分辨痘疹的阴阳属性；痘点显现时活动灵活，最切忌浮肿；出痘要参差不齐（有先后次序），血液宜归于正常附着状态，耳后、颈部、心胸部位的痘疹少于其他部位为佳，眉棱骨、两颧骨、额头前部光亮润泽且不滞涩为妙。如果一出痘就全部发出来的，病情必然严重。疮疹夹杂出现的，属于半轻半重的情况。出痘稀少，内外微微发红的，属于轻症。外表黑而内里赤红的，属于轻微严重。外表白而内里黑的，属于非常严重。痘顶端出现黑点，像针孔一样的，说明热毒剧烈且病势极重。痘色青紫干枯、凹陷，伴有昏睡、出汗、烦躁、发热、口渴，腹部胀满、啼哭喘息，大小便不通畅的，属于危困之象。凡是痘色光润红活的，说明气血调和且旺盛。颜色惨暗的，说明气血衰弱。气旺盛则血能听从气的指挥，气衰弱则血被气所囚困，血没有气就不能收束毒素，气没有血就不能化解毒素，确实是这样吗？痘毒必须依靠气血才能从头到尾发挥疗效。然而，颜色发红，是毒邪刚开始外出的表现；颜色发白，是毒邪尚未解除的表现；颜色发黄，是毒邪即将解除的表现；黄色腻滑，是毒邪完全解除的表现。颜色灰白的，是血衰和气滞的表现；颜色焦褐色的，是气血枯竭的表现；颜色焦紫色的，是凶险淫邪毒炽盛结聚的表现；颜色发黑的，是毒邪停滞而血液干涸的表现。由红变白，由白变黄的，主生；由红变紫，由紫变黑的，是死亡的征兆。又有血与毒邪相互搏结，形成虚壳，虽然看起来圆满，但实际上是空壳虚泡且颜色枯白的。又有气血都离散，而邪火浮游，所以虽然看到红晕尚存，但是气虚不能接续，血虚不能化生，所以逐渐变得干枯萎缩的，这些情况都需要详细辨别，不可轻视。
When variola (smallpox) and rubeola (measles) erupt, if the body heat is mild and spreads outward, the condition will inevitably be mild; if there is internal distress, confusion, irritability, and stagnation of pathogenic factors within, the condition will inevitably be severe. This is the natural progression of the disease's momentum. Therefore, the color of the lesions should be valued for being moist and lustrous, while dullness is disliked; brightness is valued, while dryness and roughness are disliked; a pale red hue is valued, while blackish stagnation is disliked; a round and clean shape is valued, while fragmentation is disliked; elevation is valued, while flatness is disliked; sparsity is valued, while density is disliked; the skin texture should be firm and solid, while vacuity and thinness are disliked. When the base of the pustule tightens, it helps distinguish between Yin and Yang aspects of the eruption. The appearance of spots should be active and flexible; edema is strictly contraindicated. The eruption should be uneven in timing (staggered), blood should return to its proper attachment, and fewer eruptions behind the ears, on the neck, chest, and heart area compared to other parts are preferable. Smoothness and luster without stagnation on the brow ridge, zygomatic arches, and forehead are ideal. If all eruptions appear simultaneously upon onset, the condition must be severe. Cases where sores are accompanied by rashes are considered half-mild and half-severe. Eruptions that are sparse with slight redness inside and out indicate a mild condition. Black exterior with red interior indicates slightly severe. White exterior with black interior indicates extremely severe. Black dots at the apex of the sores, resembling needle holes, indicate intense heat and extreme severity. Cyanosis, dryness, purple depression, lethargy, sweating, irritability, fever, thirst, abdominal distension, crying, panting, and constipation of both urine and feces indicate a critical state. Generally, if the color of the sores is lustrous and vibrant red, it indicates harmonious and vigorous Qi and Blood. If the color is dreary and dark, it indicates decline of Qi and Blood. When Qi is vigorous, Blood follows its command; when Qi declines, Blood is imprisoned by it. Without Qi, toxins cannot be contained; without Blood, toxins cannot be resolved. Indeed, the toxin of smallpox requires Qi and Blood to complete its course from beginning to end. However, a red color indicates the toxin is just beginning to emerge; white indicates the toxin has not yet resolved; yellow indicates the toxin is about to resolve; greasy yellow indicates the toxin is completely resolved. Grayish-white indicates Blood decline and Qi stagnation; scorched brown indicates exhaustion of Qi and Blood; scorched purple indicates fierce accumulation of evil toxins; black indicates toxin stagnation and drying of Blood. A change from red to white, or white to yellow, signifies survival. A change from red to purple, or purple to black, is an omen of death. There are also cases where Blood struggles with the toxin, forming a hollow shell; although appearing round and full, it is actually an empty, flaccid blister with withered white color. In cases where both Qi and Blood have separated, and the fire of the pathogen floats freely, although a red halo remains, Qi deficiency fails to sustain it, and Blood deficiency fails to transform it, leading to gradual withering and drying. These conditions require careful differentiation and should not be taken lightly.