Centers for Disease Control and Prevention. Guidance for diagnosis and reporting of cases has been issued by these organizations. Classification Debate has occurred about whether Kawasaki disease should be viewed as a characteristic immune response to some infectious pathogen, as an autoimmune process, or as an autoinflammatory disease (i.e. involving innate rather than adaptive immune pathways). Overall, immunological research suggests that Kawasaki disease is associated with a response to a conventional antigen (rather than a superantigen) that involves both activation of the innate immune system and also features of an adaptive immune response. Identification of the exact nature of the immune process involved in Kawasaki disease could help guide research aimed at improving clinical management. Inflammation, or vasculitis, of the arteries and veins occurs throughout the body, usually caused by increased production of the cells of the immune system to a pathogen, or autoimmunity. Systemic vasculitides may be classified according to the type of cells involved in the proliferation, as well as the specific type of tissue damage occurring within the vein or arterial walls. Under this classification scheme for systemic vasculitis, Kawasaki disease is considered to be a necrotizing vasculitis (also called necrotizing angiitis), which may be identified histologically by the occurrence of necrosis (tissue death), fibrosis, and proliferation of cells associated with inflammation in the inner layer of the vascular wall. Other diseases involving necrotizing vasculitis include polyarteritis nodosa, granulomatosis with polyangiitis, Henoch–Schönlein purpura, and eosinophilic granulomatosis with polyangiitis. Kawasaki disease may be further classified as a medium-sized vessel vasculitis, affecting medium- and small-sized blood vessels, such as the smaller cutaneous vasculature (veins and arteries in the skin) that range from 50 to 100 µm in diameter. Kawasaki disease is also considered to be a primary childhood vasculitis, a disorder associated with vasculitis that mainly affects children under the age of 18. A recent, consensus-based evaluation of vasculitides occurring primarily in children resulted in a classification scheme for these disorders, to distinguish them and suggest a more concrete set of diagnostic criteria for each. Within this classification of childhood vasculitides, Kawasaki disease is, again, a predominantly medium-sized vessel vasculitis. It can also be classed as an autoimmune form of vasculitis. It is not associated with anti-neutrophil cytoplasmic antibodies, unlike other vasculitic disorders associated with them (such as granulomatosis with polyangiitis, microscopic polyangiitis, and eosinophilic granulomatosis with polyangiitis). This form of categorization is relevant for appropriate treatment. Treatment Children