IL6 and necrotizing vasculitis: HSP was originally considered a Th1-mediated systemic vasculitis with cytokine cascades and endothelial cell lesions in small vessels in the acute stage.9,11,29 Th1-related serum cytokines such as IL-1, IL-6, and tumor necrotic factor levels and soluble IL-2 receptor expressions are often elevated in the acute phase of HSP.9,11,29 In contrast, there have also been several reports of elevated Th2-related biomarker levels in children with HSP.10,12,30,31 Allergic diseases are caused by inappropriate Th2 cell-mediated immunological responses to allergens.