CONGRESS ABSTRACT

This report presents a case of a teenager with Kawasaki disease (KD) complicated by macrophage activation syndrome (MAS), an overlap condition presenting initially as myocarditis. The patient arrived with persistent fever, rash, and conjunctivitis, along with cardiac dysfunction marked by reduced ejection fraction on echocardiography and elevated cardiac laboratory markers (troponin and BNP). Initial investigations ruled out common viral and bacterial infections. Initial clinical picture suggested myocarditis. In the following days the patient developed worsening symptoms, including persistent spiking fever, erythema multiforme, hepatosplenomegaly, monolateral cervical lymphoadenopathy, thrombocytopenia, hypoalbuminemia, increased liver enzyme and significant elevation in ferritin and triglycerides, a diagnosis of high-risk KD overlapping with MAS was established. Early intervention with intravenous corticosteroids and immunoglobulins led to a rapid improvement in clinical status and resolution of cardiac dysfunction (in about 12 hours). The case emphasizes the necessity for early recognition and multidisciplinary intervention in atypical KD presentations, particularly when MAS is suspected. MAS, a potentially fatal hyperinflammatory condition associated with systemic immune activation, requires prompt treatment to prevent progression to multi-organ failure. This case highlights the broad spectrum of KD presentations, even in adolescents, who are less commonly affected by KD. Additionally, it underscores the importance of re-evaluating diagnoses as new symptoms arise, thus minimizing cognitive biases in the clinical process.