疮疹发热，先腰痛者最忌。经曰∶腰者，肾之府也。又曰∶太阳所至为腰痛。盖足太阳膀胱经为十二经之首，
其脉侠脊，入循膂，络肾，疮疹之毒起于右肾之下，循足太阳膀胱散于诸经，乃邪由里传表也，如初发热其腰即痛，
此邪由膀胱直入于肾，故关节不利而腰痛，亟解毒以泻少阴之邪，发表以通太阳之经，使邪气不得以
深入，疮虽稠密，或可愈也。治若少缓，则太阳之邪由表以传于阳，少阴之邪由里
以传于阴，表里受病，阴阳俱伤，荣卫之脉不行，脏腑之气皆绝，或为黑陷，或为
痒塌，终莫能救矣。
凡发热便腰痛者，先服人参败毒散（初热），次服五苓散加独活、细辛主之。
〔薛〕痘疮而见腰痛证者，皆因肾经虚怯，相火内燥，真阴不能胜邪，故腰作痛也，急服地黄丸以防变黑归肾，
乃克有济。大抵此痘因禀赋肾家精气不足，故目睛多白，俗谓之折腰痘是也，若平素面白，眼白睛多，行迟语迟者，
出痘必归肾经，预为调补肾气，庶免此患。一小儿十三岁，眼睛多白，或时面赤，常患颈痛，尺脉洪数。先君谓禀肾
气虚。用地黄丸料煎服而愈。至十五岁出痘，先君云须多服前药，仍用地黄丸、益气汤，更加倦怠，乃以地黄丸大剂
煎与恣饮，又用大剂八珍汤，痘渐出如式，恪服前药，至期岁，二药计十七斤余而愈。先君每见婴儿白睛多，面
色白，或色赤，令其预补脾肾，以防出痘，但信者少耳。一小儿出痘，腰痛、足热、发渴。此禀肾虚火动也。先君用
大剂加减八味丸料煎与恣饮，诸证渐退，佐以大剂八珍加紫草、糯米数剂，脓渐灌，仍用前药而结痂，用八珍汤而靥。
一小儿出痘将愈，因停食泄泻，作渴腰痛。此脾肾虚弱也。先君用加减八味丸料及五味
异功散，渴泻顿止，又与六味丸料及八珍汤而靥。一小儿面色常白，目睛多白，
时常腰痛，两足时热，冬不衣绵，年九岁。先君谓禀肾虚。令每日服地黄丸，至十岁出痘，腰痛发渴，面赤饮冷，用
地黄丸每剂加肉桂半钱，煎与恣饮，数剂之后，热渴顿止，腰痛顿愈，却去肉桂，仍与服之，至五十余剂而靥。
加味地黄丸
熟地黄（酒浸，蒸透，晒干、八两，酒拌，杵膏） 山茱萸肉 干山药 五味子（炒。各四两） 泽泻
白茯苓 牡丹皮 鹿茸（炙。各三两） 肉桂（浓者，去皮取肉一两，发热者，以此加之，引虚火归肾经，
而热自止也）
上，各另为末，入地黄和匀，量入米糊丸服。煎服更好。
羌活当归汤 治腰背痛，初发热时便宜服之。
羌活 当归 独活 防风 川芎 黄柏（各一钱） 柴胡（一钱五分） 桂枝（七分） 栀仁 红花（各八分）
酒水各半，煎服。又方，治腰痛，有苍术、汉防己。
如神汤 治腰痛。
当归 桂皮 玄胡索
各等分，为末。酒下二三钱。
When fever occurs with sores and rashes, the initial appearance of lower back pain is most taboo. The classics state: "The loins are the mansion of the Kidney." It also states: "What arrives from the Taiyang (Greater Yang) manifests as lower back pain." The Foot-Taiyang Bladder Meridian is the head of the twelve meridians; its vessel runs alongside the spine, enters along the paravertebral muscles, and connects to the Kidneys. The toxic pathogen of sores and rashes originates below the right Kidney, spreads along the Foot-Taiyang Bladder Meridian to various meridians, representing the transmission of evil from the interior to the exterior. If lower back pain occurs immediately upon the onset of fever, this indicates that the pathogen has entered the Kidney directly from the Bladder, causing joint stiffness and lower back pain. One must urgently resolve toxicity to drain the Shaoyin (Lesser Yin) pathogen and release the exterior to unblock the Taiyang meridian, preventing the pathogen from penetrating deeper. Although the sores may be dense, recovery might still be possible. If treatment is delayed even slightly, the Taiyang pathogen will transmit from the exterior to the Yang aspect, and the Shaoyin pathogen will transmit from the interior to the Yin aspect. Both the exterior and interior will be diseased, both Yin and Yang will be injured, the Ying (Nutritive) and Wei (Defensive) vessels will cease to circulate, and the Qi of the Zang-Fu organs will be exhausted. This may result in black depression of the sores or itching and collapse, ultimately becoming incurable.
For those who experience lower back pain upon the onset of fever, first administer Renshen Baidu San (Ginseng Detoxification Powder) [for initial heat], followed by Wuling San (Five-Ingredient Poria Pill) added with Du Huo (Radix Angelicae Pubescentis) and Xi Xin (Asari Radix et Rhizoma).
[Xue Ji] Lower back pain appearing during smallpox is due to deficiency and weakness of the Kidney Meridian, internal dryness of Ministerial Fire, and the inability of True Yin to overcome the pathogen, thus causing pain in the loins. Urgently administer Dihuang Wan (Rehmannia Pill) to prevent transformation into the "Black Returning to Kidney" syndrome, which is the only way to achieve efficacy. Generally, these smallpox cases stem from congenital insufficiency of Essence and Qi in the Kidney system, resulting in eyes with excessive white sclera, commonly known as "Broken Waist Smallpox." If a child typically has a pale complexion, excessive white sclera, delayed walking, and delayed speech, the smallpox will inevitably involve the Kidney Meridian. Preemptively regulate and tonify Kidney Qi to avoid this disaster. A thirteen-year-old child had excessive white sclera, occasional facial redness, frequent neck pain, and a surging, rapid Chi (Cun Cun) pulse. My father diagnosed it as congenital Kidney Qi deficiency. He was cured by decocting and administering Dihuang Wan material. At fifteen years old, when he contracted smallpox, my father advised continuing the previous medication, using Dihuang Wan and Yiqi Tang (Qi-Supplementing Decoction). As fatigue worsened, large doses of Dihuang Wan were decocted for him to drink freely, combined with large doses of Bazhen Tang (Eight-Treasure Decoction). The sores gradually emerged normally. Strict adherence to the previous medications led to scabbing at the appropriate time, with over seventeen jin (approx. 8.5 kg) of the two medicines consumed in total before recovery. Whenever my father observed infants with excessive white sclera, pale faces, or reddish complexions, he instructed preemptive tonification of the Spleen and Kidney to prevent complications during smallpox eruption, though few believed him. Another child developed smallpox accompanied by lower back pain, hot feet, and thirst. This indicated congenital Kidney deficiency stirring empty fire. My father prescribed large doses of Jiajian Bawei Wan (Modified Eight-Ingredient Pill) for free consumption, after which symptoms gradually subsided. This was supplemented with large doses of Bazhen Tang plus Zi Cao (Arnebiae Radix et Rhizoma) and Nuomi (Oryzae Semen Glutinosae) for several doses until pus filled the sores. The previous medicine was continued for scabbing, and Bazhen Tang was used for final healing. Another child, nearing recovery from smallpox, suffered from food stagnation-induced diarrhea, thirst, and lower back pain due to Spleen and Kidney weakness. My father used Jiajian Bawei Wan material and Wuwei Yigong San (Five-Ingredient Extraordinary Efficacy Powder), which instantly stopped thirst and diarrhea. Liuwei Wan material (Six-Ingredient Pill) and Bazhen Tang were then given for final healing. Another child, aged nine, had a constant pale face, excessive white sclera, frequent lower back pain, hot feet, and refused cotton clothing in winter. My father attributed this to congenital Kidney deficiency and ordered daily administration of Dihuang Wan. At ten years old, upon developing smallpox with lower back pain, thirst, facial redness, and preference for cold drinks, Dihuang Wan was modified with half a qian (approx. 3g) of Rou Gui (Cinnamomi Cortex) per dose for free consumption. After several doses, heat and thirst ceased instantly, and lower back pain resolved completely. Rou Gui was then removed, and the base formula continued for over fifty doses until healing.
Jiawei Dihuang Wan (Modified Rehmannia Pill)
Shu Dihuang (Prepared Rehmanniae Radix, soaked in wine, steamed through, dried, eight liang, mixed with wine, pounded into paste) Shan Zhu Yu (Corni Fructus) Gan Shan Yao (Dioscoreae Rhizoma) Wu Wei Zi (Schisandrae Fructus, stir-fried, four liang each) Ze Xie (Alismatis Rhizoma) Bai Fu Ling (Poria) Mu Dan Pi (Moutan Cortex) Lu Rong (Cervi Cornu Pantotrichum, roasted, three liang each) Rou Gui (Cinnamomi Cortex, thick bark, peeled, one liang; add if feverish to guide deficient fire back to the Kidney meridian, thereby stopping heat).
Grind each ingredient separately into fine powder, mix evenly with the Rehmannia paste, add an appropriate amount of rice paste to form pills. Decoction is preferable.
Qianghuo Danggui Tang (Notopterygii and Angelicae Sinensis Decoction) Treats lower back and back pain; suitable for early administration during initial fever.
Qiang Huo (Notopterygii Rhizoma et Radix) Dang Gui (Angelicae Sinensis Radix) Du Huo (Pubescentiae Radix) Fang Feng (Saposhnikoviae Radix) Chuan Xiong (Chuanxiong Rhizoma) Huang Bo (Phellodendri Cortex, one qian each) Chai Hu (Bupleuri Radix, one qian five fen) Gui Zhi (Cinnamomi Ramulus, seven fen) Zhi Ren (Gardeniae Semen) Hong Hua (Carthami Flos, eight fen each).
Decoct with half wine and half water. Another prescription for lower back pain includes Cang Zhu (Atractylodis Rhizoma) and Han Fang Ji (Stephaniae Tetrandrae Radix).
Rushen Tang (Miraculous Divine Decoction) Treats lower back pain.
Dang Gui (Angelicae Sinensis Radix) Gui Pi (Cinnamomi Cortex) Yan Hu Suo (Corydalis Rhizoma)
Equal parts, grind into powder. Take two to three qian with wine.