立斋曰∶足跟乃督脉发源之所，肾经所过之地。若饮食失节，起居失宜，亏足三阴经，
则成疮矣。若漫肿寒热，或体倦少食，属脾虚下陷也，用补中益气汤。若晡热作痛，头目不清
，属脾虚阴火也，前汤并六味丸。若痰涎上升，或口舌生疮，属肾水干涸也，前汤并加减八
味丸。凡此皆当滋其化源，若治其外则误矣。俗云，兔啮疮者，盖猎人被兔咬足跟，或疮久
而不敛，必气血沥尽而死。若人脚跟患此，亦终难愈，因名兔啮也。
一男子，素不慎起居，内热引饮作渴，体倦两足发热，后足跟作痛。或用清热除湿之剂
，更加发肿。又服败毒之药， 赤痛甚。复用清热祛毒，溃裂番张，状如赤榴，热痛如锥，
内热晡热。此以足三阴亏损，朝用十全大补汤，夕用加减八味丸，外敷当归膏，两月余而愈
。其服消毒等药而殁者，不能枚举。
太尹陈汝邻，两腿酸软，或赤或白，足跟患肿，或痛或痒后痛，而或如无皮，或如皱裂
，日晡至夜，胀痛 热。用补中益气汤，加八味丸料，补其肝肾而愈。
一男子，患足跟疮肿痛，服消毒散，搽追蚀药，虚证叠出，形体骨立，自分必死。余用
十全大补汤兼山药、山茱萸，两月余而愈。
一妇人，两足发热，两跟作痛，日晡热甚。余以为肝肾血虚，用加减逍遥散、六味地黄
丸，五十余剂而愈。
杨锦衣，脚跟生疮如豆许，痛甚，状似伤寒。以还少丹、内塞散治之，稍可。次因纳宠
作痛，反服攻毒药，致血气愈弱，腿膝痿弱而死。盖足跟乃二FS 发源之处，肾经所由之地。
若疮口不合，则FS 气不能发生，肾气由此而泄，故为终身之疾。况彼疮先得于虚，复不知戒
，虽大补气血，犹恐不及，安可服暴悍攻毒之药，以戕贼之乎。（俱薛按）
薛立斋说：足跟是督脉发源的地方，也是肾经经过的区域。如果饮食没有节制，起居不规律，导致足三阴经（足太阴脾经、足少阴肾经、足厥阴肝经）亏损，就会形成疮疡。如果出现漫肿、寒热交替，或者身体疲倦、食欲减退，属于脾气虚弱、中气下陷，使用补中益气汤。如果在下午发热并疼痛，头目昏沉不清爽，属于脾气虚弱导致的阴火，用前一种方剂配合六味丸。如果有痰涎上涌，或者口舌生疮，属于肾水枯竭，用前一种方剂配合加减八味丸。所有这些情况都应当滋养其化生之源，如果只治疗外部症状就错了。民间俗称“兔啮疮”，据说猎人被兔子咬伤足跟，或者疮疡长久不愈合，必然因为气血耗尽而死。如果人的脚跟患上这种病，也最终难以痊愈，因此命名为兔啮。
有一个男子，平时不注意起居养生，内热导致想喝水解渴，身体疲倦且两脚发热，后来足跟开始疼痛。有人给他用清热除湿的药剂，反而更加肿胀。又服用败毒的药物，患处红肿疼痛加剧。再次使用清热祛毒的方法，导致疮口溃烂翻卷，形状像红色的石榴，灼热疼痛如针锥刺入，伴有内热和下午发热。这是因为足三阴经亏损，早晨服用十全大补汤，晚上服用加减八味丸，外部敷贴当归膏，两个多月后痊愈。那些服用消毒等药物而死亡的案例，无法一一列举。
太尹陈汝邻，双腿酸软，有时发红有时发白，足跟患肿，有时疼痛有时瘙痒，之后疼痛，皮肤有时像没有皮一样，有时像皱纹裂开，从下午到夜晚，胀痛且有热感。使用补中益气汤，加入八味丸的药料，补益肝肾而痊愈。
有一个男子，患足跟疮肿痛，服用消毒散，涂抹追蚀药，虚证接连出现，形体消瘦如骨立，自己断定必死无疑。我用十全大补汤兼加山药、山茱萸，两个多月后痊愈。
有一个妇人，两脚发热，两脚跟疼痛，下午发热严重。我认为这是肝肾血虚，使用加减逍遥散、六味地黄丸，五十多剂后痊愈。
杨锦衣，脚跟生出像豆子大小的疮，疼痛剧烈，症状类似伤寒。用还少丹、内塞散治疗，稍微好转。后来因为纳妾纵欲导致疼痛，反而服用攻毒药，导致血气更加虚弱，腿膝痿弱而死。因为足跟是督脉发源之处，肾经所由之地。如果疮口不能愈合，则督脉之气不能发生，肾气由此泄露，所以成为终身的疾病。况且他的疮最初是由于虚损引起的，又不加戒慎，即使大力补益气血，恐怕还来不及，怎么可以服用猛烈悍毒的药物来残害他呢？（以上均为薛己按语）
Xue Lizhai stated: The heel is the origin of the Du Meridian (Governing Vessel) and the pathway of the Kidney Meridian. If diet is irregular, daily routine is improper, leading to deficiency of the Three Yin Meridians of the Foot (Spleen, Kidney, Liver), sores will form. If there is diffuse swelling with alternating chills and fever, or fatigue and poor appetite, it belongs to Spleen Qi deficiency with sinking; use Buzhong Yiqi Tang (Tonify the Middle and Augment the Qi Decoction). If there is afternoon fever with pain, and a cloudy sensation in the head and eyes, it belongs to Yin fire due to Spleen deficiency; use the aforementioned decoction combined with Liuwei Wan (Six-Ingredient Pill with Rehmannia). If phlegm-saliva rises, or sores appear on the mouth and tongue, it belongs to exhaustion of Kidney Water; use the aforementioned decoction combined with Jiaban Bawei Wan (Modified Eight-Ingredient Pill). All these cases require nourishing their source of transformation; treating only the exterior would be a mistake. The common saying refers to "Rabbit-Bite Sore," supposedly named because hunters bitten on the heel by rabbits, or those whose sores fail to heal for a long time, eventually die from depletion of Qi and Blood. If a person's heel suffers from this, it is ultimately difficult to cure, hence the name Rabbit-Bite.
A man, who had always neglected his daily routine, suffered from internal heat causing thirst and desire to drink, fatigue, and heat in both feet, followed by pain in the heels. Someone administered herbs for clearing heat and draining dampness, which caused further swelling. He then took herbs to defeat toxins, resulting in severe redness and pain. Upon reusing methods to clear heat and remove toxins, the sore ulcerated and everted, resembling a red pomegranate, with burning pain like a needle cone, accompanied by internal heat and afternoon fever. This was due to deficiency of the Three Yin Meridians of the Foot. He took Shiquan Dabu Tang (Ten-Agent Great Tonifying Decoction) in the morning and Jiaban Bawei Wan (Modified Eight-Ingredient Pill) in the evening, with external application of Danggui Gao (Angelica Ointment), and healed after more than two months. Cases of death due to taking detoxifying herbs cannot be enumerated.
Chen Rulin, Grand Administrator, suffered from soreness and weakness in both legs, sometimes red, sometimes white, with swelling in the heels, alternating pain and itching, followed by pain, where the skin appeared denuded or wrinkled and cracked. From afternoon to night, he experienced distending pain and heat. He used Buzhong Yiqi Tang (Tonify the Middle and Augment the Qi Decoction) added with ingredients of Bawei Wan (Eight-Ingredient Pill), tonifying the Liver and Kidneys, and was cured.
A man suffered from painful swelling of a heel sore. After taking Xiaodu San (Detoxification Powder) and applying Zhichi medicine (Corrosive/Promoting Ulceration Medicine), multiple deficiency syndromes emerged, his body became emaciated as if only bones remained, and he believed he would certainly die. I used Shiquan Dabu Tang (Ten-Agent Great Tonifying Decoction) supplemented with Shan Yao (Dioscoreae Rhizoma) and Shan Zhu Yu (Corni Fructus), and he healed after more than two months.
A woman suffered from heat in both feet and pain in both heels, with severe heat in the afternoon. I considered this to be Blood deficiency of the Liver and Kidney, and used Jiaban Xiaoyao San (Modified Free and Easy Wanderer Powder) and Liuwadihuang Wan (Six-Ingredient Rehmannia Pill), healing after more than fifty doses.
Yang Jinyi, a Guard of Honor, developed a bean-sized sore on his heel, with severe pain, resembling symptoms of Shanghan (Cold Damage). It was treated with Huanshao Dan (Return to Youth Pill) and Neisai San (Internal Blocking Powder), showing slight improvement. Later, due to sexual indulgence, pain recurred. He mistakenly took attacking/toxic drugs, causing his Qi and Blood to weaken further, leading to flaccidity of the legs and knees and eventual death. Since the heel is the origin of the Du Meridian and the path of the Kidney Meridian, if the sore does not close, the Du Meridian Qi cannot arise, and Kidney Qi leaks out, resulting in a lifelong ailment. Moreover, since the sore originated from deficiency, and he failed to exercise caution, even great tonification of Qi and Blood might not suffice; how could one administer fierce and toxic drugs to harm him? (All are notes by Xue Ji)