Histologically, the small vessels in the lower level of the dermis showed endothelial cell proliferations, thrombosis, fibrin plugs and hyaline degeneration.

• 皮肤组织病理检查见真皮浅层小血管内皮细胞增生,少数管腔闭锁,血管壁有纤维蛋白样物质沉积和透明变性。