An Unexpected Diagnosis of Kawasaki Disease in a Three-Month-Old Infant: A Diagnostic Trap.

Kawasaki disease (KD) is an acute systemic vasculitis predominantly affecting young children and can lead to serious cardiac complications if not diagnosed and treated promptly. Diagnosing KD in infants younger than six months is challenging due to atypical or incomplete presentations, increasing the risk of cardiovascular complications. The purpose of this case report was to detail the clinical presentation, laboratory findings, and cardiac outcomes in a patient diagnosed with KD during the first three months of life. The infant's initial symptoms were misleading, as the prolonged fever was initially attributed to pyelonephritis, leading to an antibiotic treatment that did not resolve the fever. The overlap of KD symptoms with other febrile illnesses and the subtle or absent classical signs of KD in this age group often complicate the diagnosis. This case underscores the importance of considering KD in infants under six months with persistent fever and highlights diagnostic challenges, including misinterpretation of symptoms. Early echocardiography and high clinical suspicion are crucial for timely diagnosis and management to prevent severe cardiac complications in this vulnerable age group.