Exogenous febrile diseases are a category of illnesses caused by external pathogens, primarily characterized by fever. This category encompasses various infectious and contagious diseases recognized in modern clinical practice, such as the common cold, influenza, severe acute respiratory syndrome, and COVID-19.
PART.01Overview of the Pathogenesis of Exogenous Febrile Diseases in TCM
The study of exogenous diseases in Traditional Chinese Medicine (TCM) has evolved over a long period, gradually forming a systematic and continuously improving theoretical framework, along with a wealth of clinical experience.
The Huangdi Neijing summarizes the achievements in disease prevention and treatment prior to the Qin and Han dynasties, laying the theoretical foundation for TCM. Chapters such as Suwen: Lun Re Pian, Su Wen: Ci Re Pian, Su Wen: Ping Re Bing Lun Pian, and Ling Shu: Re Bing introduce concepts like “febrile diseases,” “cold damage,” and “epidemic diseases,” discussing the etiology, pathogenesis, clinical manifestations, and prevention of exogenous febrile diseases. The Su Wen Yi Pian, Volume 3: Ci Fa Lun succinctly presents the characteristics of diseases, stating that “all epidemics are easily transmitted, regardless of size, with similar symptoms,” and outlines the prevention strategies of “preserving the vital qi within” and “avoiding toxic qi.”
In the late Eastern Han dynasty, Zhang Zhongjing advocated for a diagnostic and treatment model that integrates “disease, pulse, and syndrome” by compiling works such as Su Wen, Jiu Juan, Ba Shi Yi Nan, Yin Yang Da Lun, and Tai Lu Yao Lu, resulting in the Shang Han Za Bing Lun comprising sixteen volumes. He established a system for differentiating and treating exogenous febrile diseases, focusing on the patterns of transmission in the six meridians of cold damage, and created practical formulas such as Ma Huang Tang (Ephedra Decoction), Gui Zhi Tang (Cinnamon Twig Decoction), Ma Xing Shi Gan Tang (Ephedra, Apricot Kernel, Gypsum, and Licorice Decoction), Bai Hu Tang (White Tiger Decoction), and Xiao Chai Hu Tang (Minor Bupleurum Decoction), achieving a qualitative leap in the prevention and treatment of exogenous diseases.
In the Northern Song dynasty, Pang Anshi authored the Shang Han Zong Bing Lun, positing that warm diseases are caused by aberrant toxic qi. He combined the five elements and six meridians with the organs and meridians to differentiate and treat warm diseases, incorporating cold herbs into Ma Huang Tang and Gui Zhi Tang, with prescriptions often dominated by large amounts of gypsum.
In the Jin dynasty, Liu Wansu promoted the theory that “all six qi arise from fire transformation,” emphasizing that “febrile diseases can only be treated with heat, not with cold medicine,” and created the Feng Tong Sheng San (Wind-Expelling and Clear-Resolving Powder), providing new ideas and methods for treating exogenous febrile diseases.
In the Ming dynasty, Wu Youke wrote the Wen Yi Lun, establishing the “li qi” theory of etiology, clearly stating that “the disease of warm epidemic is not caused by wind, cold, heat, or dampness, but by a different kind of qi in the world.” This concept foreshadowed the idea of pathogenic microorganisms, marking a significant leap in the etiology of exogenous diseases. In terms of treatment, he advocated for purgation, emphasizing that “the guest pathogen should be expelled early,” and noted that “there are over thirty symptoms that can be purged, not all need to be present,” leaving valuable repeatable experiences for future generations.
In the Qing dynasty, with the continuous refinement of the theory of exogenous febrile diseases, new differentiation systems (such as Wei Qi, Ying Blood differentiation, and San Jiao differentiation), diagnostic methods, and effective formulas (such as Yin Qiao San and Sang Ju Yin) were applied clinically, leading to new advancements in TCM’s prevention and treatment of exogenous febrile diseases.
Since modern times, the influx of Western learning and the blending of different academic schools, along with the collision of TCM and Western medicine theories and practices, have enriched and developed the theoretical system of TCM regarding exogenous febrile diseases.
PART.02Initiating Pathogenesis and Treatment Strategies for Exogenous Febrile Diseases
As a category of diseases, exogenous febrile diseases inevitably have commonalities and patterns during their occurrence, development, and transformation. It is crucial to dynamically and comprehensively study exogenous febrile diseases to identify the initiating pathogenesis. When discussing pathogenesis, it is essential to analyze the location and nature of the disease. When the warm pathogen invades, it first affects the lungs. The lungs open to the nose, are externally connected to the skin, and govern the defensive qi. Therefore, after the onset, the defensive qi becomes obstructed, leading to symptoms such as fever, chills, body aches, nasal congestion, runny nose, and sore throat. The lungs govern respiration and are responsible for dispersing and descending, indicating that as the disease progresses and the righteous and evil qi contend, symptoms such as cough, phlegm production, and shortness of breath may subsequently appear. Furthermore, based on the relationship between the organs, as the disease progresses, complex clinical phenomena may arise, such as “sweating followed by renewed fever, with a rapid pulse, not due to sweat deficiency, and wild talk of inability to eat.” Based on this analysis, it is believed that in the initial stage of the disease, the evil resides in the lung’s defensive layer, with the key pathogenesis being the obstruction of the lung by evil qi and the stagnation of the defensive qi. Therefore, the treatment focus should prioritize expelling the evil, while also supporting the righteous qi to stabilize the area not yet affected by the evil, preventing disease progression and deterioration.
PART.03Analysis of the Formulation of Lianhua Qingwen
Lianhua Qingwen is one of the representative Chinese patent medicines for treating exogenous febrile diseases. Analyzing its composition, the formula includes key ingredients from traditional famous formulas such as Ma Xing Shi Gan Tang, Feng Tong Sheng Wan, and Yin Qiao San, while also drawing on the experience of using Da Huang (Rhubarb) from Wu Youke’s Wen Yi Lun, effectively integrating the essence of four generations of famous formulas. From an efficacy perspective, it also reflects the consistency of the formula and syndrome.
Based on the analysis of the initial pathogenesis of exogenous febrile diseases, the treatment emphasizes expelling the evil as the primary principle. Lianhua Qingwen achieves the therapeutic goal of expelling evil through several aspects.
Dispersing and Releasing the Exterior
Releasing the exterior is an important method for expelling evil. The Lianhua Qingwen formula primarily consists of exterior-releasing herbs, such as the cool and dispersing Lian Qiao (Forsythia) and Jin Yin Hua (Honeysuckle), as well as the warm and dispersing Ma Huang (Ephedra) and Xing Ren (Apricot Kernel). The formula employs both cold and warm herbs to achieve the effect of releasing the exterior and inducing sweating. As stated in the classics, “If there is evil, it will be soaked into the body to produce sweat; if it is on the skin, it will be released through sweating.” In the early stages of the disease, it is essential to release the exterior. Although there are distinctions between cool and warm exterior-releasing herbs, considering the clinical reality of exogenous febrile diseases being prone to transformation and heat, the combination of both types better meets the therapeutic needs. Regarding the sweating effect of cool herbs, Hua Xiuyun once stated: “Cool and dispersing opens the lungs, which is a sweating agent.” This statement can inspire a more comprehensive understanding and application of the exterior-releasing method.
Unblocking the Orifices and Facilitating Excretion
The lungs open to the nose, which is the pathway for external pathogens to invade the body and also the channel for expelling evil. In the late Ming dynasty, Jia Suoxue in Yao Pin Hua Yi: Qi Yao stated that Huo Xiang (Agastache) has a fragrant qi that can unblock the nine orifices. In addition to the aforementioned cool and dispersing effects, the peppermint in the formula, which also has the characteristic of aromatic transformation, works well with Huo Xiang to effectively unblock the nasal orifices, alleviating nasal and pharyngeal symptoms while facilitating the expulsion of evil qi through the nasal passages. This is one of the characteristics of this formula.
Facilitating the two excretions (urination and defecation) is also a channel for expelling evil. In the Jin dynasty, Liu Wansu created Feng Tong Sheng Wan to release the exterior and clear the interior, using Da Huang and Mang Xiao to guide the heat evil out through the stool. Wu Youke in the Ming dynasty skillfully used Da Huang to “drive out toxic filth” for treating epidemics. In the Qing dynasty, Liu Songfeng in Songfeng Shuo Yi analyzed Wu Youke’s preference for using Da Huang, stating: “Although Da Huang is cold, its nature is to move and not to hold. When epidemics cause stagnation, this can help disperse the evil.” Combining the theory of the lungs and large intestine being interrelated, the use of Da Huang in the formula becomes significant. Bitter Apricot Kernel is slightly warm and belongs to the lung and large intestine meridians; it not only has the effect of stopping cough and relieving wheezing but also facilitates bowel movements. It has been found that during the heat toxin stage of exogenous febrile diseases, using Da Huang to purge the bowels can reduce the absorption of toxins in the intestines, alleviate endotoxemia, and decrease the release of inflammatory mediators, thereby improving symptoms. Based on the initiating pathogenesis, the lungs are the organ affected by the evil, and the lungs govern the regulation of water pathways, making urination an important route for expelling evil. The Ma Huang in the formula also has the effect of unblocking the water pathways, combining its warm and dispersing properties with the therapeutic evidence. In the Ming dynasty, Xue Ji in Yao Xing Ben Cao stated that Lian Qiao “is primarily used to unblock and facilitate the five lin (dysuria).” The Qing dynasty’s Fen Lei Cao Yao Xing recorded that Yu Xing Cao (Houttuynia) can “treat the five lin and reduce edema.”
Aromatic Transformation of Turbidity
In the Qing dynasty, Wu Jutong in Wen Bing Tiao Bian stated: “Warm epidemics… often accompany turbidity.” Turbidity can be divided into exogenous and endogenously generated. The invasion of turbid qi into the body, along with various pathogenic factors leading to disorder in the internal environment, results in the production of turbid qi during metabolic processes, which is an inevitable phenomenon in the pathogenesis of exogenous febrile diseases. This has been corroborated by experiences and related research in infectious disease prevention and control over the past thirty years. This “turbid qi” should be regarded as evil qi. Therefore, transforming turbidity becomes an important aspect of expelling evil. In the formulation of Lianhua Qingwen, the aforementioned Huo Xiang and peppermint are representative herbs for aromatic transformation, significantly improving symptoms such as chest tightness, epigastric fullness, vomiting, and nausea caused by dampness or turbid qi.
Clearing and Resolving Heat
The invasion of external pathogens, including epidemic toxins, is the initiating factor of exogenous febrile diseases. After the onset, the contention between the righteous and evil qi, along with toxic metabolic products and various inflammatory factors, are significant contributors to symptoms such as fever and transformation, manifesting clinical signs consistent with TCM’s concept of “heat toxin.” Therefore, clearing and resolving heat becomes a method of treatment for exogenous febrile diseases. The Lianhua Qingwen formula fully embodies this principle. In the Qing dynasty, Yu Jiayan in Detailed Discussion on Warm Epidemics to Break Great Confusion stated: “Preventing disease before it occurs, pre-drinking aromatic herbs, righteous qi medicine, prevents evil from entering; this is the best. Once evil has entered, urgently expel the filth, which is the primary principle. The upper jiao is like mist, rising and expelling it, while also detoxifying; the middle jiao is like a stew, loosening and expelling it, while also detoxifying; the lower jiao is like a drain, clearing and expelling it, while also detoxifying.” This emphasizes the importance of detoxification, which should be integrated throughout the treatment of the disease. In the Lianhua Qingwen formula, in addition to Lian Qiao and Jin Yin Hua for clearing heat and detoxifying, the combination of Mian Ma Guan Zhong, Ban Lan Gen (Isatis), and Yu Xing Cao enhances the detoxifying power. Licorice is also an important herb for clearing heat and detoxifying. Regarding clearing heat and resolving fire, gypsum is a representative herb, embodying the treatment philosophy of simultaneously addressing the defensive qi.
In terms of supporting the righteous qi, it is emphasized that “when the righteous qi is preserved within, the evil cannot invade.” A low immune system significantly increases the likelihood of developing exogenous febrile diseases, and after onset, it may lead to prolonged illness or even various complications. Even with normal immunity, the body can still be damaged under the strong attack of potent evil. Therefore, protecting the righteous qi and enhancing immune defense and recovery capabilities are of great importance in the prevention and treatment of exogenous febrile diseases. The Lianhua Qingwen formula includes Hong Jing Tian (Rhodiola) which has the effects of tonifying qi, invigorating blood, clearing heat, and moistening the lungs. Chinese Tibetan Medicine states that Hong Jing Tian can “nourish the lungs, clear heat, replenish the original qi, and treat lung diseases.” Modern research shows it has antiviral, anti-inflammatory, immune-regulating, anti-hypoxia, anti-fatigue, and protective effects on pulmonary microvascular endothelial cells. Licorice also has the effects of tonifying the spleen, benefiting qi, harmonizing the middle, and alleviating urgency. Supporting the righteous qi is also reflected in the simultaneous treatment of the defensive qi and the lungs and intestines, treating early to stabilize areas not yet affected by evil, thus protecting the righteous qi.
Conclusion
In summary, Lianhua Qingwen effectively addresses the rapid onset and transformation of exogenous febrile diseases, reflecting treatment methods that align with the pathogenesis. Its formulation is precise, skillfully balancing the relationships between clearing and resolving, dispersing cold and promoting lung function, supporting the righteous qi and expelling evil, which conforms to TCM theory and aligns with clinical practice, making it one of the representative Chinese patent medicines for treating exogenous febrile diseases.
Author: Professor Chen Xianhai, Shandong University of Traditional Chinese Medicine Affiliated Hospital