In the acute phase of the disease, changes in the peripheral extremities can include erythema of the palms and soles, which is often striking with sharp demarcation and often accompanied by painful, brawny edema of the dorsa of the hands or feet, so affected children frequently refuse to hold objects in their hands or to bear weight on their feet. Later, during the convalescent or the subacute phase, desquamation of the fingers and toes usually begins in the periungual region within two to three weeks after the onset of fever and may extend to include the palms and soles. Around 11% of children affected by the disease may continue skin-peeling for many years. One to two months after the onset of fever, deep transverse grooves across the nails may develop (Beaus lines), and occasionally nails are shed.The most common skin manifestation is a diffuse macular-papular erythematous rash, which is quite nonspecific. The rash varies over time and is characteristically located on the trunk; it may further spread to involve the face, extremities, and perineum. Many other forms of cutaneous lesions have been reported; they may include scarlatiniform, papular, urticariform, multiform-like erythema, and purpuric lesions; even micropustules were reported. It can be polymorphic, not itchy, and normally observed up to the fifth day of fever. However, it is never bullous or vesicular.In the acute stage of Kawasaki disease, systemic inflammatory changes are evident in many organs. Joint pain (arthralgia) and swelling, frequently symmetrical, and  arthritis can also occur.
The highest rate of progression to stenosis occurs among those who develop large aneurysms. The worst prognosis occurs in children with giant aneurysms. This severe outcome may require further treatment such as percutaneous transluminal angioplasty, coronary artery stenting, bypass grafting, and even cardiac transplantation.A relapse of symptoms may occur soon after initial treatment with IVIG. This usually requires rehospitalization and retreatment. Treatment with IVIG can cause allergic and nonallergic acute reactions, aseptic meningitis, fluid overload, and rarely, other serious reactions. Overall, life-threatening complications resulting from therapy for Kawasaki disease are exceedingly rare, especially compared with the risk of nontreatment. Evidence indicates Kawasaki disease produces altered lipid metabolism that persists beyond the clinical resolution of the disease.Rarely, recurrence can occur in Kawasaki disease with or without treatment. Epidemiology
Kawasaki disease affects boys more than girls, with people of Asian ethnicity, particularly Japanese people. The higher incidence in Asian populations is thought to be linked to genetic susceptibility. Incidence rates vary between countries. Currently, Kawasaki disease is the most commonly diagnosed pediatric vasculitis in the world. By far, the highest incidence of Kawasaki disease occurs in Japan, with the most recent study placing the attack rate at 218.6 per 100,000 children less than five years of age (about one in 450 children). At this present attack rate, more than one in 150 children in Japan will develop Kawasaki disease during their lifetimes.However, its incidence in the United States is increasing. Kawasaki disease is predominantly a disease of young children, with 80% of patients younger than five years of age.