Incomplete Kawasaki Disease Complicated by Shock: A Diagnostic Challenge in a Child.

Kawasaki disease (KD) is an acute vasculitis of medium-sized vessels that primarily affects children. It can present with incomplete or atypical features, leading to diagnostic delay and increased risk of cardiovascular complications. Kawasaki disease shock syndrome (KDSS) is a rare but severe manifestation characterized by hemodynamic instability and heightened inflammatory response. We report the case of an eight-year-old previously healthy boy who presented with fever and unilateral cervical lymphadenitis following recent travel. Initial evaluation suggested an infectious etiology, and he was treated with broad-spectrum antibiotics without clinical improvement. KD was suspected, and he was treated with intravenous immunoglobulins (IVIG) despite not fulfilling the full criteria for KD. Subsequently, he developed a diffuse maculopapular rash, non-purulent conjunctivitis, strawberry tongue, and escalating inflammatory markers, increasing the suspicion of incomplete KD. Despite initial treatment with intravenous immunoglobulin (IVIG), the patient acutely deteriorated with hypotension and respiratory distress, requiring intensive care admission and inotropic support. Repeat echocardiography later demonstrated coronary artery dilation and reduced left ventricular systolic function, confirming the diagnosis of KD complicated by shock. He was successfully treated with a second dose of IVIG, high-dose aspirin, and systemic corticosteroids, with subsequent clinical and hemodynamic recovery. This case highlights the diagnostic challenges of incomplete KD, the need for heightened clinical suspicion in children with persistent fever and hyperinflammation, and the need for early recognition and aggressive management of Kawasaki shock syndrome to prevent cardiac complications.