论曰∶足三阴经，皆起于足，气血沮而不行，溃于指甲之间，能成甲疽，凡以经络之所
流注，非特肌肉之病也。故或得于剪甲伤肌，或得于甲长侵肉，或得于屦凫之不适，使血气
沮遏
治其
治甲疽日夜倍增，赤肉生甲边裹甲者。 茹膏方
茹 黄 （各二两） 猪脂（半斤）
上三味，先 咀如豆，以苦酒浸一宿，与猪脂一处，微火上煎取三合，绞去滓，以涂疮
上，日三两度，其赤肉即消散。
治甲疽肿烂，生脚指甲边，赤肉努出，时瘥时发。方
雄黄（半两） 蛇蜕皮（烧灰一分）
上二味，同研如粉，每用先以温泔洗疮令软，以尖刀子，割去甲角拭干，以药敷之，用
软帛裹之，半日许药湿，即易之，一日即除，其痛便止。
治甲疽及诸痈疽恶疮，有息肉。猪蹄汤方
猪蹄（一只生者） 白蔹 白芷 野狼牙 芍药（各三两） 黄连 黄芩 大黄 独活（各
二
两）
上八味， 咀如豆，先以水三斗，煮猪蹄水至一斗二升，去蹄后入药，更煮至五升，候
温洗疮，日三度。
治甲疽， 肉裹甲，脓血疼痛不瘥。乳香散敷方
乳香（研） 胆矾（烧灰研）
上二味等分，再同研极细，时时敷之，大凡此疾，须是剔去甲，不疗亦愈，或已成疮久
不瘥，即用此方。
治甲疽。绿矾散敷方
绿矾（二两）
上一味，熨斗内以炭火烧令通赤，去火研令极细，先以盐汤洗疮拭干，旋敷疮上，将软
帛裹缚，如疮急痛，即以酥涂疮上，令润，日三五度用。
治甲疽 肉疼痛，脓血不止。石胆散敷方
石胆（半两）
上一味， 过细研，敷疮上，日三两度。
治甲疽。白矾散敷方
白矾（烧灰一两） 麝香 芦荟 蚺蛇胆（各半分）
上四味，合研极细，先以浆水洗疮拭干敷之，日三两上，以瘥为度。
治甲疽多年不瘥， 肉脓血疼痛。乌梅散敷方
乌梅（十枚烧灰）
上一味，研为散，敷疮上，日三易。
治甲疽。黄 散敷方
黄 （锉） 蛇蜕皮（炙令焦各一两）
上二味，捣罗为散，敷疮上，日三五度。
治甲疽。马齿散敷方
墙上马齿菜（阴干一两） 木香 丹砂（研细） 盐（研细各一分）
上四味，除丹砂盐外，锉碎拌令匀，于熨斗内，以炭火烧过，取出细研，即入丹砂盐末
。再研匀，旋取敷疮上，日三两度。
Commentary states: The three Yin meridians of the foot all originate from the feet. If Qi and Blood stagnate and fail to circulate, ulceration occurring between the nails can result in Onychia (Jia Ju). This is primarily due to obstruction in the flow and distribution of the meridians, rather than merely a disease of the muscles. Therefore, it may arise from injury to the flesh during nail trimming, from nails growing too long and invading the flesh, or from ill-fitting footwear, causing the stagnation and suppression of Qi and Blood.
Formula for treating Onchia where symptoms worsen day and night, with red flesh growing around the nail edge and enveloping the nail:
Ruhu Ointment Formula (Ruhu Gao Fang)
Ruhuang (2 liang), Huangqin (Coptidis Rhizoma, 2 liang), Pig Fat (Pancreas Suis, 0.5 jin).
The above three ingredients are first chopped like beans, soaked in vinegar (Ku Jiu) overnight, then combined with pig fat. Simmer over low heat until 3 he of liquid remains, strain off the dregs, and apply to the sore. Apply 3-4 times daily; the red flesh will dissipate.
Formula for treating Onychia with swelling and ulceration at the side of the big toenail, with protruding red flesh, recurring intermittently:
Xionghuang (Realgar, 0.5 liang), Shed Snake Skin (She Tu Pi, burned to ash, 1 fen).
The above two ingredients are ground together into powder. Before each use, wash the sore with warm rice water to soften it, cut away the nail corner with a sharp knife, dry the area, and apply the powder. Wrap with soft cloth. Change the dressing when the medicine becomes damp after about half a day. It cures within one day, and pain ceases immediately.
Pig Trotter Soup Formula for treating Onychia, various carbuncles and malignant sores with polyps:
Pig Trotter (one raw), Bai Lian (Ampelopsis Radix), Bai Zhi (Angelicae Dahuricae Radix), Ye Lang Ya (Sarcandrae Herba), Shao Yao (Paeoniae Radix Alba) (each 3 liang), Huang Lian (Coptidis Rhizoma), Huang Qin (Scutellariae Radix), Da Huang (Rhei Radix et Rhizoma), Du Huo (Angelicae Pubescentis Radix) (each 2 liang).
The above eight ingredients are chopped like beans. First, boil the pig trotter in 3 dou of water until reduced to 1.2 dou. Remove the trotter, add the herbs, and boil further until reduced to 5 sheng. When warm, wash the sore with this decoction, three times daily.
Muxiang Powder for external application for treating Onychia where red flesh envelops the nail, with purulent blood and pain not healing:
Ruxiang (Frankincense, ground), Danfan (Chalcanthite, burned to ash and ground).
The above two ingredients are mixed in equal parts and ground extremely fine. Apply frequently as needed. Generally, for this condition, removing the nail is necessary; even without treatment, it may heal. However, if the sore has persisted for a long time without healing, use this formula.
Lvfan Powder for external application for treating Onychia:
Lvfan (Melanteritum, 2 liang).
The above single ingredient is heated in an ironing pan with charcoal until red hot, removed from fire, and ground extremely fine. Wash the sore with salt water and dry it, then apply the powder. Bind with soft cloth. If the sore is painful and urgent, apply butter (Su) to moisten the area. Use 3-5 times daily.
Shidan Powder for external application for treating Onychia with red flesh pain and continuous purulent bleeding:
Shidan (Chalcanthite, 0.5 liang).
The above single ingredient is ground finely and applied to the sore, 3-4 times daily.
Bai Fan Powder for external application for treating Onychia:
Bai Fan (Alumen, burned to ash, 1 liang), She Xiang (Moschus, 0.5 fen), Lu Hui (Aloe, 0.5 fen), Ran She Dan (Python Bile, 0.5 fen).
The above four ingredients are mixed and ground extremely fine. Wash the sore with fermented rice water (Jiang Shui), dry it, and apply the powder. Apply 3-4 times daily until healed.
Wumei Powder for external application for treating chronic Onychia not healing for years, with red flesh, purulent blood, and pain:
Wu Mei (Fructus Mume, ten pieces, burned to ash).
The above single ingredient is ground into a powder and applied to the sore. Change the dressing three times daily.
Huangbo Powder for external application for treating Onychia:
Huang Bo (Phellodendri Cortex, sliced), She Tu Pi (Shed Snake Skin, roasted until scorched, each 1 liang).
The above two ingredients are pounded and sifted into a powder. Apply to the sore, 3-5 times daily.
Machi Powder for external application for treating Onychia:
Qiang Shang Ma Chi Cai (Portulacae Herba dried in shade, 1 liang), Mu Xiang (Aucklandiae Radix), Dan Sha (Cinnabaris, ground fine), Yan (Salt, ground fine, each 1 fen).
The above four ingredients, excluding Cinnabar and Salt, are chopped and mixed evenly. Heat in an ironing pan with charcoal, remove, and grind finely. Then add Cinnabar and Salt powders. Grind uniformly again. Apply to the sore as needed, 3-4 times daily.