疮痘无论疏密，只要毒出得尽而无留伏，其发以渐而透，其收以期而净，岂尚有余毒哉！若出
不能尽，发不能透，收不能齐，其人自有余热，或渴而腹痛吐泻，或小便赤涩，大便秘结，精神昏
惯，四体倦怠，饮食减
少，坐卧不安，是皆余毒未净之证。凡出之净者，作三四次出，大小不一，至成浆收靥之时，于疮
空中犹有补出者，此皆出之尽也。若只始出一层，后无补空之痘，此必尚有伏也，又发之透者，必
于手足候之，盖手足部远，气不易达，若能充拓饱满，浆气颇足，可谓发之透也。若只平 不能成
脓，此毒虽出而未能旁达四肢，必有留而伏者。又收之齐者，自面而下，痂皮洁净，中无溃烂可谓
之齐。若收之太早，或不成痂，此必有内陷之毒也。凡若此者，皆有余毒，须察部位经络、寒热虚
实，或补或利，或解或散，以平为期。若治之不应不已者，此坏证也，不必妄行攻击。
一、尽后发热不减者，此有虚实二证，如能食而烦渴，小便赤，大便秘者，实也。宜四顺清凉饮
、三黄丸之类主之。若痘后余毒未净，有诸热证者，惟大连翘饮为最佳。如大便不秘，小便不赤，
坐卧振摇，饮食少进者虚也，宜调元汤，或五福饮加芍药之类主之。
《心鉴》云∶痘后余热者，虚热也。虚热多发于午后，脸赤唇红，或妄言谵语，切不可作实热
治，当用调元汤，或保元汤加黄连，热甚者，宜大连翘饮。若妄用攻下，使胃气一虚，则变生他患
，致成坏证，不可治矣。
徐氏曰∶痘后余热不除者，当量其轻重而治之，大热则利小便，小热则宜解毒。盖利其小水，
使心火有所导引，虽不用凉药，而余热自无容留矣。小热宜解毒者，盖小热不解，恐大热渐至矣。
利水者，宜导赤散；解毒者，宜犀角地黄汤。若但身表发热而别无他证者，止宜柴胡麦门冬散。
痘疮无论出得稀疏还是密集，只要毒邪能完全透发出来而没有潜伏残留，其发作是逐渐透发的，其结痂脱落是按预期时间干净完成的，哪里还会有余毒呢！如果出痘不能出尽，透发不能透彻，收靂（结痂脱落）不能整齐，病人自然会有余热，或者口渴且腹痛、呕吐腹泻，或者小便颜色红赤且排尿涩痛，大便秘结，精神昏沉困倦，四肢倦怠无力，饮食减少，坐卧不安，这些都是余毒没有清除干净的证候。凡是出痘干净的，会分三四次陆续发出，大小不一，到了成浆和结痂的时候，在原本空瘪的痘疮处还有新发出的痘粒，这都算是出痘出尽了。如果只开始发出一层，后来没有填补空缺的新痘，这必定还有毒邪潜伏。另外，透发透彻的，必须在手足部位观察，因为手足部位距离躯干较远，气血不容易到达，如果能充盈饱满，浆气充足，可以称为透发透彻。如果只平塌不能化脓，这说明毒邪虽然发出了但不能通达四肢，必定有留滞潜伏的。另外，收靂整齐的，从面部向下，痂皮洁净，中间没有溃烂，可以称为整齐。如果收靂太早，或者不能形成痂皮，这必定有内陷的毒邪。像这样的情况，都有余毒，必须考察病变部位的经络、寒热虚实属性，采用补益或通利，或解表或消散的方法，以身体平衡为准则。如果治疗无效且病情不止，这是坏证，不必胡乱使用攻伐之法。
一、出痘后发热不退的，这有虚证和实证两种情况。如能进食且烦躁口渴，小便红赤，大便秘结的，属于实证。适宜用四顺清凉饮、三黄丸之类的方剂主治。如果是痘后余毒未净，出现各种热证的，以大連翘饮效果最佳。如果大便不秘结，小便不红赤，坐卧时身体颤动摇晃，饮食少量进服的，属于虚证，适宜用调元汤，或者五福饮加芍药之类的方剂主治。
《心鉴》说：痘后的余热，属于虚热。虚热多在午后发作，面色发红嘴唇红润，或者胡言乱语说梦话，切不可当作实热来治疗，应当用调元汤，或者保元汤加黄连，热势严重的，适宜用大连翘饮。如果胡乱使用攻下法，使胃气一旦虚弱，就会变生其他祸患，导致成为坏证，就无法治愈了。
徐氏说：痘后余热不消除的，应当衡量病情的轻重来治疗，大热则通过利小便来治疗，小热则适宜解毒。因为通利小便，能使心火有所引导疏导，即使不使用凉药，而余热自然没有容身留存的地方了。小热适宜解毒的，是因为小热如果不解除，恐怕大热会逐渐到来。利水的，适宜用导赤散；解毒的，适宜用犀角地黄汤。如果只是体表发热而没有其他症状的，只适宜用柴胡麦门冬散。
Regardless of whether the smallpox lesions are sparse or dense, as long as the pathogenic toxins are fully expelled without remaining latent, their eruption occurs gradually and thoroughly, and their crusting and healing occur cleanly within the expected timeframe, how could there be residual toxins? If the lesions do not erupt completely, fail to develop thoroughly, or heal unevenly, the patient will naturally have residual heat. Symptoms may include thirst accompanied by abdominal pain, vomiting, and diarrhea; red and scanty urine with dysuria; constipation; mental confusion and lethargy; fatigue in the four limbs; reduced appetite; and restlessness in sitting and lying down. These are all signs that residual toxins have not been cleared. When eruptions are clean, they appear in three or four waves, varying in size. Even at the stage of pustule formation and crusting, new lesions may emerge in previously empty sites, indicating complete eruption. If only an initial layer appears with no subsequent filling of gaps, it indicates latent toxins remain. Regarding thorough development, one must observe the hands and feet, as Qi and Blood are less likely to reach these distal areas. If the lesions are full and plump with sufficient pus fluid, it can be considered thoroughly developed. If lesions remain flat and fail to suppurate, although toxins have emerged, they have not reached the extremities, implying lingering latent pathogens. Regarding even healing, from the face downward, if the scabs are clean without ulceration, it is considered even. If healing occurs too early or fails to form scabs, it implies internal sinking of toxins. In such cases, residual toxins exist. One must examine the meridians and locations involved, as well as patterns of cold/heat and deficiency/excess, employing tonification or purgation, release or dispersion, aiming for balance. If treatment fails and the condition persists, it constitutes a deteriorated syndrome (Huai Zheng), and aggressive attack therapies should not be used recklessly.
1. Fever persisting after eruption may stem from either deficiency or excess syndromes. If the patient can eat, feels irritable and thirsty, has red urine, and constipation, it is an excess syndrome. It is appropriate to treat with Sishun Qingliang Yin (Four-Obedience Cooling Decoction) or Sanhuang Wan (Three-Yellow Pill). If residual toxins remain post-smallpox presenting with various heat symptoms, Dalianqiao Yin (Large Forsythia Decoction) is optimal. If stool is not constipated, urine is not red, the patient trembles while sitting or lying, and food intake is minimal, it is a deficiency syndrome. It is appropriate to treat with Tianyuan Tang (Origin-Regulating Decoction) or Wufu Yin (Five-Fortune Decoction) added with Shaoyao (Paeonia Root).
The *Xin Jian* states: Residual heat after smallpox is deficient heat. Deficient heat often manifests in the afternoon, with a red face and lips, or delirious speech. It must never be treated as excess heat. Instead, use Tianyuan Tang or Baoyuan Tang (Protect-the-Origin Decoction) added with Huanglian (Coptis Rhizome). For severe heat, Dalianqiao Yin is suitable. If purgatives are used recklessly, damaging Stomach Qi, other complications may arise, leading to an incurable deteriorated syndrome.
Xu Shi stated: For persistent residual heat after smallpox, treatment should be based on severity. High fever requires promoting urination; mild heat requires resolving toxins. Promoting urination guides Heart Fire outward, allowing residual heat to dissipate even without cooling herbs. Mild heat requires toxin resolution because unresolved mild heat may progress to high fever. For promoting urination, Daochi San (Guide Out the Red Powder) is suitable; for resolving toxins, Xijiao Dihuang Tang (Rhinoceros Horn and Rehmannia Decoction) is suitable. If there is only superficial fever without other symptoms, Chaihu Maidong San (Bupleurum and Ophiopogon Powder) alone is appropriate.