小儿心胃火盛，廉泉穴开，则口中流水不绝。
又曰∶因大人与小儿嘻戏，捏其腮颊，则令小人淌口水。
俗云∶孕妇思食酸甜不得，则婴儿多淌口水。
验方（《急救》）用热水一盆，入白矾一勺，将儿两足频频洗之，立瘥。
又方 鱼在小儿嘴上揩之。
《医论选要》曰∶夫口者，脾之窍，诸经多有会于口者。盖五味入口，藏于脾胃，
为之运化津液，以养五气，节宣微爽，五脏之气偏胜，由是诸疾生焉。故口疮者，乃
脾气凝滞，加之风热，治当清胃泻火。
冯鲁瞻曰∶口疮者，心脾蕴热也。小儿阴气未生，阳气偏盛，又因将养过温，心
脾积热，熏蒸于上而成疮。治宜泻心化毒，清凉为主。若月内诸病，而口无涎沫者凶。
又曰∶凡口舌生疮，初起不可便用凉药敷掺，恐寒凝不散，内溃奔走，久而难
愈。必先用辛轻升散，而后清凉，使郁火达外，再视其所因而治之。更有中气不足，
脾胃虚衰，不能敛纳下焦，阴火被逼上炎，以致虚阳口疮。丹溪所谓∶劳役过度，虚
火上炎，游行无制，舌破口疮，又当从理中汤加附子治之。若作实热，误投凉药，则
害又不止口疮矣。
又曰∶口疮者，上焦实热，中焦虚寒，下焦阴火，各经传变所致，当分别治之。如
发热、作渴、饮冷，实火也。轻则用补中益气，重则用六君子汤。饮食少思，大便
不实，中气虚也，用人参理中汤。手足逆冷，肚腹作痛，中气虚寒，用附子理中汤。
晡热、内热，不时而热，血虚也，用八物加丹皮、五味、麦冬。发热、作渴、吐痰，
小便频数，肾水虚也，用八味丸。日晡发热，或热从小腹起，阴虚也，用四物、参、
术、五味、麦冬；不应，则用加减八味丸。若热来复去，昼见夜伏，夜见昼伏，不时
而动，或无定处，或从脚起，乃无根之火也。亦用前丸及十全大补加麦冬、五味，更
以附子末唾津调抹涌泉穴。若概用寒凉，损伤生气，为害匪浅。或问∶虚寒何以生口
疮，而反用附子理中耶？盖因胃虚谷少，则所胜者肾也，水气之逆而乘之，反为中寒，
脾胃衰微之火，被迫炎上，作为口疮。经曰∶岁金不及，炎火乃行，复则寒雨暴至，
阴厥乃格，阳反上行，民病口疮是也。故用参术、甘草补其土，姜、附散其寒，火
得所助，则接引退舍矣。
小儿心胃火气旺盛，廉泉穴开启，导致口中津液流个不停。
又说：因为大人与小孩嬉戏时捏其脸颊，致使小孩流口水。
民间常说：孕妇想吃酸甜之物却吃不到，婴儿就会多流口水。
验方（出自《急救》）：用一盆热水，加入一勺白矾，频繁清洗孩子的双脚，立刻痊愈。
另一个方子：用鱼在孩子嘴上擦拭。
《医论选要》说：口是脾的窍道，多条经脉都汇聚于口。大概五味入口，储藏于脾胃，由脾胃运化津液，以滋养五脏之气，若调节稍有失调，五脏之气偏盛，各种疾病便由此产生。所以口疮，是由于脾气凝滞，加上风热侵袭，治疗应当清胃泻火。
冯鲁瞻说：口疮，是心脾蕴积热毒所致。小儿阴气尚未生成，阳气偏盛，又因养育过于温热，导致心脾积热，熏蒸于上部而成疮。治疗宜泻心解毒，以清凉为主。如果满月内的婴儿患其他病，且口中没有涎沫的，预后凶险。
又说：凡是口舌生疮，初起时不可立即使用凉药敷贴掺撒，恐怕寒性凝滞不散，导致邪气内溃扩散，时间久了难以治愈。必须先用辛轻升散的药物，然后再用清凉药，使郁结之火发散到体表，再根据病因进行治疗。更有中气不足，脾胃虚衰，不能收敛接纳下焦之气，导致阴火被逼上炎，以致形成虚阳口疮。丹溪所说：劳役过度，虚火上炎，游行无制，导致舌破口疮，此时应当从理中汤加附子来治疗。如果当作实热证，误投凉药，那么危害就不止于口疮了。
又说：口疮，是上焦实热，中焦虚寒，下焦阴火，各经传变所致，应当分别治疗。如发热、口渴、想喝冷水，是实火。轻症用补中益气汤，重症用六君子汤。饮食减少思虑，大便不成形，是中气虚，用人参理中汤。手足逆冷，肚腹疼痛，是中气虚寒，用附子理中汤。傍晚发热、内热，不时发热，是血虚，用八物汤加牡丹皮、五味子、麦冬。发热、口渴、吐痰，小便频数，是肾水虚，用八味丸。下午发热，或热从小腹升起，是阴虚，用四物汤、人参、白术、五味子、麦冬；无效，则用加减八味丸。如果热势来来去去，白天出现晚上潜伏，晚上出现白天潜伏，不时发作，或位置不定，或从脚部发起，这是无根之火。也用前面的丸药及十全大补汤加麦冬、五味子，再用附子末配唾液涂抹涌泉穴。如果一概使用寒凉药，损伤生机，危害不小。有人问：虚寒为何生口疮，反而用附子理中汤呢？这是因为胃虚谷少，所胜者（肾）水气之逆而乘之，反成中寒，脾胃衰微之火，被迫炎上，形成口疮。经文说：岁金不及，炎火乃行，复则寒雨暴至，阴厥乃格，阳反上行，民病口疮是也。所以用人参、白术、甘草补益脾土，干姜、附子散其寒，火得到帮助，就会退避舍去。
When a child's Heart and Stomach fire is excessive, the Lianquan acupoint opens, causing continuous drooling from the mouth.
It is also said: When adults play with children and pinch their cheeks, it causes the child to drool.
Folklore states: If a pregnant woman desires sour or sweet foods but cannot obtain them, her infant will tend to drool excessively.
Empirical prescription (from *Ji Jiu*): Use a basin of hot water, add one spoonful of Alum (*Bai Fan*), and frequently wash the child's feet; recovery will be immediate.
Another method: Rub fish on the child's mouth.
*Yi Lun Xuan Yao* states: The mouth is the orifice of the Spleen, and many meridians converge there. Generally, the five flavors enter the mouth and are stored in the Spleen and Stomach, where they are transformed into fluids to nourish the Qi of the Five Zang organs. If regulation is slightly impaired, the Qi of the Five Zang organs becomes excessive in certain aspects, giving rise to various diseases. Therefore, mouth ulcers result from stagnation of Spleen Qi compounded by Wind-Heat; treatment should focus on clearing the Stomach and purging Fire.
Feng Luzhan stated: Mouth ulcers are caused by Heat accumulation in the Heart and Spleen. Children have not yet generated sufficient Yin Qi, while Yang Qi is relatively excessive. Furthermore, if nurtured too warmly, Heat accumulates in the Heart and Spleen, steaming upwards to form sores. Treatment should involve purging the Heart and resolving toxicity, primarily using cooling methods. For infants within one month of age suffering from other illnesses, if there is no saliva in the mouth, the prognosis is ominous.
It is also said: In cases of oral and lingual sores, cool medicines should not be applied immediately at the onset, as cold nature may cause stagnation and prevent dispersion, leading to internal ulceration and spread, making long-term healing difficult. One must first use pungent and light ascending-dispersing herbs, followed by cooling agents, to allow constrained Fire to reach the exterior, and then treat according to the specific etiology. Additionally, deficiency of Middle Qi and decline of the Spleen and Stomach can fail to consolidate and accept Qi from the Lower Jiao, forcing Yin Fire to flare upwards, resulting in mouth ulcers due to deficient Yang. As Danxi described: Excessive labor leads to deficient Fire flaring upwards, wandering without restraint, causing tongue breaks and mouth ulcers; in such cases, *Lizhong Tang* (Regulate the Middle Decoction) with added Aconite (*Fu Zi*) should be used. If mistaken for excess Heat and treated with cooling medicines, the harm would extend beyond mere mouth ulcers.
It is further stated: Mouth ulcers can result from Excess Heat in the Upper Jiao, Deficient Cold in the Middle Jiao, and Yin Fire in the Lower Jiao, transmitted through various meridians; thus, they must be treated differently. For symptoms such as fever, thirst, and desire for cold drinks, this indicates Excess Fire. Mild cases use *Buzhong Yiqi Tang* (Tonify the Middle and Augment the Qi Decoction); severe cases use *Liujunzi Tang* (Six Gentlemen Decoction). For reduced appetite and loose stools, indicating Middle Qi deficiency, *Renshen Lizhong Tang* (Ginseng Regulate the Middle Decoction) is used. For cold extremities and abdominal pain, indicating Middle Qi Deficient Cold, *Fuzi Lizhong Tang* (Aconite Regulate the Middle Decoction) is prescribed. For afternoon fever, internal heat, and intermittent fever, indicating Blood deficiency, *Bawu Tang* (Eight Substances Decoction) with added Moutan Cortex (*Dan Pi*), Schisandra Berry (*Wu Wei Zi*), and Ophiopogon Tuber (*Mai Dong*) is used. For fever, thirst, expectoration, and frequent urination, indicating Kidney Water deficiency, *Bawei Wan* (Eight Ingredients Pill) is administered. For afternoon fever or heat rising from the lower abdomen, indicating Yin deficiency, *Siwu Tang* (Four Substances Decoction) combined with Ginseng (*Ren Shen*), Atractylodes Rhizome (*Bai Zhu*), Schisandra Berry (*Wu Wei Zi*), and Ophiopogon Tuber (*Mai Dong*) is used; if ineffective, *Jiajian Bawei Wan* (Modified Eight Ingredients Pill) is employed. If the fever comes and goes, appearing during the day and hiding at night, or vice versa, occurring irregularly, or moving unpredictably, or starting from the feet, this is Rootless Fire. The aforementioned pills, along with *Shiquan Dabu Tang* (Ten Complete Tonifying Decoction) plus Ophiopogon Tuber (*Mai Dong*) and Schisandra Berry (*Wu Wei Zi*), should be used. Additionally, Aconite powder mixed with saliva should be applied to the Yongquan acupoint. If cold-cooling medicines are indiscriminately used, damaging vital energy, the harm will be significant. One might ask: How can Deficient Cold produce mouth ulcers, warranting the use of *Fuzi Lizhong Tang*? This is because when the Stomach is deficient and grain intake is low, the controlling element (Kidney) Water Qi rebels and attacks, turning into Middle Cold. The weak Fire of the declining Spleen and Stomach is forced to flare upwards, forming mouth ulcers. The Classic states: "When Metal of the year is insufficient, Flaming Fire prevails; upon return, cold rain arrives violently, Yin reversal blocks, Yang rises inversely, and the people suffer from mouth ulcers." Therefore, Ginseng, Atractylodes, and Licorice are used to tonify Earth; Ginger and Aconite are used to disperse Cold. Once Fire receives assistance, it retreats and withdraws.