To explore the treatment of pulmonary interstitial fibrosis secondary to rheumatoid arthritis based on the concept of sanjiao "four-way membranous channels".

Sanjiao, a term of traditional Chinese medicine, which consists of the upper, middle, and lower jiao, is a membrane system that encompasses the zangfu organs. We propose the idea that sanjiao is a four-way membranous channels, internally connecting with the micro-membrane of the zangfu organs, extending to the skin, muscles, tendons, bones, and joints, by which water and fluid is transferred from the upper jiao to the middle jiao, then to the lower jiao, countering the transfer of blood and essence to promote the qi movement and generate health-promoting nutrition. Pulmonary interstitial fibrosis secondary to rheumatoid arthritis is characterized by disorders of both joints and the lung, and it is a condition in which healthy qi deficiency occurs, with phlegm and blood or intertwined that blocks the joints and lung micro-membrane. In the early stage of rheumatoid arthritis, external evils, such as wind, cold, and damp, build up in the joints of the tendons and bones, and prolonged early-stage symptoms would cause phlegm production and blood stasis which may obstruct the joints. Phlegm turbidity and blood stasis remain in the sanjiao membranous channels and stagnate the pulmonary micro-membrane, which may cause the pulmonary interstitial disease. The sanjiao four-way membranous channels is the pathway for joint phlegm and blood stasis flowing to the lungs, and sanjiao obstruction can aggravate phlegm and blood stagnation. The treatment is based on the principle of dredging, transforming, and regulating sanjiao, selecting herbs for regulating qi, promoting blood circulation and expelling wind, and using drugs that tonify the lung, warm the kidney, turn to qi, and regulate the state of zangfu organ. This unblocks the sanjiao membranous channels and dissipates the phlegm and blood stasis turbidity evil of the obstructed lung micro-membrane, and it can effectively treat pulmonary interstitial fibrosis secondary to rheumatoid arthritis. [ABSTRACT FROM AUTHOR]