Systemic Arterial Aneurysms With Limb Ischemia in a 3-Month-Old Infant: An Unusual Presentation of Incomplete Kawasaki Disease

Kawasaki disease (KD) is an acute systemic vasculitis predominantly affecting children under 5 years old, characterized by inflammation of medium-sized arteries. The most serious complication is the development of coronary artery aneurysms (CAAs), which can lead to significant cardiovascular morbidity and mortality. Although coronary artery aneurysms (CAAs) are well-documented in KD, the occurrence of systemic arterial aneurysms (SAAs) is rare and less understood. This report describes a 3-month-old male infant with probable/incomplete Kawasaki disease (KD), who presented with bilateral lower limb ischemia due to multiple systemic arterial aneurysms (SAAs) and coronary involvement. Treatment with intravenous immunoglobulin (IVIG) and aspirin led to clinical improvement. This case emphasizes the importance of recognizing incomplete forms of KD and considering differential diagnoses such as infantile polyarteritis nodosa and MIS-C.