Six-year trend of subsequent allergic diseases following Kawasaki disease and its clinical implications: A population-based matched cohort study of 34,712 patients.

BACKGROUND: It has been suggested that allergic diseases may increase after Kawasaki disease (KD). We aimed to analyze the temporal patterns of allergic disease incidence after KD. METHODS: A nationwide population-based matched cohort study was conducted using data from the Korean National Health Insurance claims database. Patients aged <5 years diagnosed with KD and their 1:3 propensity score-matched controls were included. Three cohorts were established: Cohort A, patients with allergies; Cohort B, patients without allergies; and Cohort C, patients without allergies, but excluding patients with birth history and underlying medical conditions. Cumulative incidence rates (%) and associated hospital visits for allergic rhinitis, atopic dermatitis, urticaria, and asthma were compared between the cases and controls during the 6-year follow-up period. RESULTS: The study population comprised 8678 patients diagnosed with KD and 26,034 controls. In Cohort A, although initially, there were intergroup differences in the number of hospital visits for certain allergic diseases, these differences were inconsistent and varied depending on the type of allergic disease. Over time, the differences narrowed, and by the sixth year, the gap had decreased significantly. In Cohorts B and C, the initial incidence rates of the four allergic diseases and associated hospital visits were lower in patients with KD as compared to controls. However, with a faster rate of increase, the incidence rates and number of hospital visits eventually surpassed those of the controls. CONCLUSIONS: The pattern of delayed increase in cumulative incidence rates and hospital visits for allergic diseases after KD suggests the possibility of a shared genetic or immunologic susceptibility between KD and allergic diseases, which becomes evident over time, rather than a direct influence of KD resulting in allergic diseases.

Association of Previous Antibiotics Use and Kawasaki Disease: A Cohort Study of 106,908 Patients.

BACKGROUND: Microbial imbalance in the gut from antibiotic use may be an etiologic factor of Kawasaki disease (KD). We aimed to identify the association between the use of antibiotics and the development of KD, considering various antibiotic profiles. METHODS: A population-based, case-control study was performed using data from the Health Insurance Review and Assessment Service database. Children <5 years of age, who were diagnosed with KD between 2016 and 2019, were identified. Propensity score-matched controls were selected from the general population in a 1:5 ratio. Four separate study cohorts were created according to different periods of antibiotic use: (1) within 28 days and (2) 12 months after birth and (3) within 6 months and (4) 12 months from the index date. Profiles regarding antibiotic use were compared between patients with KD and matched controls. RESULTS: We included 17,818 patients with KD and 89,090 matched controls. Use of antibiotics within 6 months [odds ratio (OR): 1.18; 95% confidence interval (CI): 1.12-1.26] and 12 months (OR: 1.23; 95% CI: 1.14-1.32) from the index date were associated with the development of KD. The association between antibiotic use and KD was most prominent in patients who had received 3 or more types of antibiotics within 12 months from the index date (OR: 1.26; 95% CI: 1.17-1.37). CONCLUSIONS: Antibiotic use within the preceding 6 or 12 months was associated with KD. Alteration in gut microbiota due to antibiotic usage might play a role in the development of KD.

Comparison of Previous Infectious and Allergic Diseases Between Patients with Kawasaki Disease and Propensity Score-matched Controls: A Nationwide Cohort Study.

OBJECTIVE: To determine whether previous infectious and allergic diseases are associated with the development of Kawasaki disease in children. STUDY DESIGN: This nationwide, population-based, case-control study used data from the Korean National Health Insurance claims database. The entire cohort consisted of patients younger than 5 years of age diagnosed with Kawasaki disease and 1:5 propensity score-matched controls from 2013 to 2019. The epidemiologic features and previous infectious or allergic diseases between the 2 groups were compared, and potential factors that could influence the association were identified. RESULTS: In total, 32 964 patients diagnosed with Kawasaki disease and 164 820 controls were included. Patients with Kawasaki disease had more frequent diagnoses of previous sepsis or bacteremia (OR 1.41), acute pyelonephritis (OR 1.10), and otitis media (OR 1.24). In addition, Kawasaki disease was associated with previous diagnoses of atopic dermatitis (OR 1.05), urticaria (OR 1.08), and asthma (OR 1.05). The association between previous infectious or allergic diagnoses and Kawasaki disease was more prominent in younger patients (<2 years). However, intravenous immunoglobulin resistance, sex, and region of residence were not significant factors that consistently influenced the association between previous infectious or allergic diseases and Kawasaki disease. CONCLUSIONS: Despite the increased rates of previous infectious and allergic diseases in patients with Kawasaki disease compared with controls, the association between allergic diseases and Kawasaki disease was weaker in our cohort than in previous studies.

Clinical characteristics of patients with recurrent Kawasaki disease: a nationwide cohort study of 19 456 patients with minimum 3-year follow up.

OBJECTIVE: To identify the clinical characteristics of patients with recurrent Kawasaki disease (KD). DESIGN: A nationwide, population-based, cohort study using the Korean National Health Insurance claims database between 2013 and 2016. PATIENTS: A total of 19 456 patients under the age of 5 years who were diagnosed with initial episode of KD were included. A minimum follow-up period of 3 years was mandatory for inclusion. MAIN OUTCOME MEASURES: The epidemiological and clinical profiles were compared between KD patients with and without recurrence. RESULTS: The overall recurrence rate of KD was 3.84% (n=748), and the median interval to recurrence was 498 days (IQR: 257-860 days). Approximately 70% of all recurrences occurred within 2 years of the initial diagnosis. The annual proportions of recurrence were 40%, 28%, 18%, 8% and 4% from the first to the fifth year following the initial episode, respectively. Recurrence rates were significantly higher in patients aged <1 year than in those aged 4-5 years (4.65% vs 2.22%) and those who showed resistance to an initial dose of intravenous immunoglobulin (IVIG) (10.00% vs 3.18%). Allergic comorbidities and coronary artery complications at the initial episode were not associated with increased rates of recurrence. CONCLUSIONS: We clearly identified the annual recurrence rates and their intervals from the initial episode according to the various factors identified, including young age and resistance to initial IVIG. Our results, based on a nationwide cohort, can be used as reference for follow-up management in patients with KD and in future studies.