Kawasaki disease in a young infant: diagnostic challenges.

Kawasaki disease (KD) is a multisystem vasculitis condition with a relatively unknown etiology. It has a high prevalence in children ages 6 months to 5 years, and patients often present with high fever, rash, cervical lymphadenopathy and mucocutaneous abnormalities. Visceral manifestations can be present, being coronary complications the most frequent. There is no diagnostic test for KD, its presentation can be complete or incomplete and, in some cases, it can be atypical. We report a case of a 3-month-old infant with 3-weeks of fever and aseptic meningitis. Infectious diseases were excluded and there was no response to antibiotics. Echocardiography was normal in the second week. Genetic test for CINCA syndrome was negative. In the third week, dilatation of coronary arteries determined Kawasaki disease's diagnosis. Prolonged fever, accompanied by nonspecific clinical symptoms were the only manifestations, becoming a challenging diagnosis. KD must be considered when prolonged fever is present, mainly in young children in whom the incomplete forms of the disease are more frequent.