210 - INCOMPLETE KAWASAKI DISEASE IN A 4-MONTH-OLD PATIENT

ABSTRACT

The diagnosis of incomplete KD should be considered in pediatric patients with persistent fever and any of the main clinical manifestations of the disease. In the population under 6 months, the only clinical manifestations may be fever and irritability. The following case follows up a 4-month-old male patient with persistent fever lasting for 3 weeks, who was diagnosed with incomplete KD with an ECHO that revealed the presence of aneurysms. 

BASE CASE

A 4-month-old male patient with a one-month history of fever, initially treated with paracetamol at a dose of 10 mg/kg, did not respond to the antipyretic. The first physician diagnosed bacterial pharyngitis and initiated treatment with amoxicillin. Despite this, the patient continued to experience the same symptoms. In search of more care, the patient went to a second-level hospital, where he was prescribed ibuprofen on an outpatient basis, but there was no improvement. The fever persisted, and after 48 hours, a generalized rash appeared, with erythema at the site of the BCG vaccine. The patient was then admitted to the second-level hospital, revealing elevated transaminases and persistent fever. An ECHO was performed, indicating aneurysms. IVIG was administered at a dose of 2 g/kg/ dosis. The patient was subsequently referred to the third-level. Despite elevated acute-phase reactants, a follow-up ECHO revealed giant aneurysms with a Z score of +11. A second dose of IVIG and five boluses of methylprednisolone at 30 mg/kg were administered. The patient remained afebrile with improved inflammatory markers. However, a repeat ECHO at 72 hours showed an increase in the size of giant aneurysms with a Z score of +29. Angiotomography was made to search distal aneurysms, which were excluded. Infliximab was administered at a dose of 5 mg/kg. The patient did not experience further enlargement of the aneurysms, leading to discharge. 

CONCLUSIONS

The clinical presentation of incomplete KD in a patient under 6 months poses a diagnostic challenge. The presence of coronary abnormalities is considered a specific criterion for diagnosis, especially in atypical or incomplete evolution. It is important to note that a negative echocardiogram at the onset of the disease does not rule out the diagnosis, as coronary abnormalities may develop in up to 25% of patients without timely treatment. The importance of timely diagnosis and treatment in a patient has a direct impact on their survival and evolution, as in this particular case that evolved into a refractory disease.