Clinical Characteristics and Outcomes of Kawasaki Disease in Infants Younger than Six Months of Age: Algerian Multicenter Study

Background and Objectives: Kawasaki disease (KD) is one of the most common immune vasculitis in children and the leading cause of acquired heart disease, which predominantly occurs in children under the age of 5 years. However, there are fewer cases of KD in infants younger than 6 months, making diagnosis more challenging. The objective is to characterize the clinical presentation and evolution of KD in infants < 6 months of age as compared to those ≥6 months in western Algeria. Methods: We retrospectively reviewed the medical records of 62 patients diagnosed with KD in western Algeria followed between January 2018 and January 2023. The data were categorized into 2 groups by age: Group A (<6 months, n=12) and Group B (≥6 months, n=50). We compared differences in laboratory data, clinical presentation, treatment response, and coronary artery outcomes between the two cohorts. Results: The majority (78%) of infants and children ≥6 months of age were initially diagnosed with KD, as compared to only 33,3% of infants <6 months. Clinical features of KD were more commonly observed in the older cohort: oral changes (90 vs. 75%, P = 0.0023), extremity changes (76 vs. 50 %, P = 0.029), and cervical lymphadenopathy (66 vs. 33.3%, P = 0.0004). Whether treated in the first 10 days of illness or after the 10th day, infants <6 months were at greater risk of developing a coronary artery aneurysm compared to KD patients ≥6 months treated at the same point in the course of illness [≤10 days (55 vs. 8,88 %, P = 0.0001) ; >10 days (66,6 vs. 6,6%, P = 0.046)]. Conclusion: Our data show that despite treatment in the first 10 days of illness, infants <6 months of age have a higher risk of developing a coronary artery aneurysm. Delay in the diagnosis leads to larger coronary artery aneurysms disproportionately in these infants. Thus, suspicion for KD should be high in this vulnerable population.