[Differentiation and treatment of chronic cough based on "sweat pore-lung collateral" theory]

The "sweat pore-lung collateral" theory represents a distinctive integration of micro-morphology and collateral disease theory in TCM. Sweat pores are distributed throughout the body, serving as gateways for the entry and exit of Qi and fluids and governing opening and closing. Lung collaterals are slender and tortuous channels responsible for the distribution of Qi and blood and governing transportation. These two systems complement and support each other, jointly forming the micro-structural foundation for the lung's functions of governing respiration and regulating water pathways. Chronic cough is characterized by a prolonged course, recurrent attacks, and difficulty in recovery, and its pathogenesis is not confined to a single Zang organ or stage. Based on the "sweat pore-lung collateral" theory, this paper proposes that the core pathogenesis of chronic cough evolves through the following stages: stagnation and closure of sweat pores, obstruction of lung collaterals, binding of stasis and toxin, and depletion of collaterals with sweat pore wasting. The key lies in the dynamic changes between dysfunctional opening-closing of sweat pores and disturbed distribution and transport of lung collaterals. Accordingly, the general therapeutic principle is to open the sweat pores and dredge the lung collaterals. In clinical practice, the disease is managed through staged differentiation and treatment in four phases. In the initial stage, exogenous wind invasion leads to stagnation and closure of sweat pores, with pathogenic factors hidden in the lung collaterals; treatment should open the sweat pores to expel pathogens, and disperse latent wind with acrid and dispersing methods to interrupt disease progression. In the middle stage, prolonged closure of sweat pores leads to impaired Qi and fluid dispersion, with phlegm-dampness accumulating into nests that block the lung collaterals; treatment should disperse stagnation, transform turbidity, free the collaterals, and eliminate the nests to prevent deeper transmission of pathogens. In the critical stage, phlegm, heat, stasis, and toxin become interlocked, with closed sweat pores and damaged collaterals, resulting in severe disease; treatment should dispel stasis, resolve toxin, open the sweat pores, and clear the collaterals to reverse the disease mechanism. In the advanced stage, pathogenic factors are partially eliminated but healthy Qi is damaged, with vacuous collaterals and sweat pore wasting, accompanied by dual depletion of Qi and Yin; treatment should tonify Qi, nourish Yin, replenish the collaterals, and restore the sweat pores to consolidate the root and ensure a favorable outcome. The four-stage treatment closely follows the evolution of sweat pore opening-closing and lung collateral patency-obstruction, progressing from exterior to interior and from excess to deficiency, with methods determined by patterns and prescriptions derived from principles. A representative case is provided to demonstrate the efficacy of this staged approach. This theoretical framework and staged differentiation-treatment system based on the "sweat pore-lung collateral" theory offer a new theoretical perspective and clinical pathway for the TCM diagnosis and treatment of chronic cough.