A. Cardiovascular: Kawasaki disease is a systemic vasculitis that primarily affects the cardiovascular system. It can lead to complications like coronary artery aneurysms and myocarditis. B. Integumentary: Although the disease presents with skin symptoms (rash, peeling), they are secondary manifestations. C. Gastrointestinal: GI symptoms may occur but are not the main focus. D. Respiratory: Kawasaki disease does not primarily involve the respiratory system.