Pathogenesis of "wind-toxin damaging collaterals" and stage-differentiation treatment in pediatric IgA vasculitis

IgA vasculitis is a common childhood vasculitis disorder. Its primary clinical manifestation is cutaneous purpura, which is often accompanied by gastrointestinal and joint symptoms. Renal involvement can present as hematuria or proteinuria. This condition is recurrent and protracted, significantly affecting the health of children. The pathogenic factors in pediatric IgA vasculitis are diverse. " Wind-toxin damaging collaterals" is presented as the core pathogenesis based on clinical practice and theoretical exploration. This concept essentially entails the latent attack of wind-toxin, collateral damage leading to blood extravasation, and healthy qi deficiency and lingering toxins, with the disease primarily located in the collateral vessels. The disease course is divided into three stages: acute, lingering, and recovery. Clinical practice should adhere to the pathogenesis principles and apply stagebased pattern differentiation and treatment. The acute stage involves wind-toxin attacking collaterals with dampness-heat accumulation. Treatment focuses on dispersing wind, clearing heat, and eliminating dampness to expel wind-toxin from the muscular exterior. The self-prescribed Qufeng Xiaodian Formula is a frequently selected modified formula. The lingering stage features latent wind-toxin in the collaterals and congealed accumulations in the kidney collaterals. Treatment aims to resolve wind-toxin, disperse stasis, and eliminate accumulation to remove densely accumulated wind-toxin. A modified Taohong Siwu Decoction is selected. The recovery stage involves deficient healthy qi with persistent wind assault and lingering toxins. Emphasis should be placed on cultivating the fundamental, strengthening the root, and nourishing yin, as well as supporting the healthy qi to dispel wind and expel toxins, while conditioning the body to prevent recurrence. A modified Guomin Decoction is selected. Clinical application emphasizes the combination of characteristic medicines, such as wind medicines to expel pathogens, insect medicines to identify collaterals, and vine medicines to unblock the meridians, to enhance the effects of identifying wind, resolving toxins, unblocking collaterals, and dispersing congealed accumulations. This study aims to systematically elaborate on the stage-based treatment strategy from the perspective of "wind-toxin damaging collaterals," providing a theoretical basis and clinical practice reference for the traditional Chinese medicine diagnosis and treatment of pediatric IgA vasculitis.