Kawasaki disease associated pulmonary involvement in infants

Kawasaki disease (KD) is an acute, self-limited multisystemic vasculitis of unknown cause. Pulmonary involvement has been reported in case reports and limited small case series, which is not commonly recognized, especially in younger patients <1 year. Here, we describe clinical and radiological features of infants with KD-associated pulmonary involvement (KD-PI).Infants with KD were retrospectively enrolled during the period January 2017 to December 2020 in Shenzhen Children's hospital. Patients with KD-PI were matched 1:1 based on current age and sex with KD patients without clinically apparent PI. Clinical data were collected from inpatient or outpatient medical records, including clinical manifestations, laboratory parameters, radiological findings, management, and prognosis.Of 248 infant patients with KD, 34 presented with KD-PI. Of these, 22 had only subtle respiratory symptoms. Compared to KD controls, patients with KD-PI had significantly higher mean Kobayashi score (mean ± SD: 2.85 ± 1.94; p = .004), more had extremely high C-reactive protein (≥10 mg/dl: 11/34, 32.3%; p = .0115) and procalcitonin levels (˃1 ng/ml: 16/34, 47%; p = .039), and more were administered with adjuvant corticosteroids as initial therapy (38.2% vs. 2.9%; p = .0005). Abnormal chest radiological findings included peripheral consolidation (97.0%), localized pleural thickening (73.0%), lobular septal thickening (70.6%), ground-glass opacities (55.9%), linear opacities (35.3%), and pleural effusion (20.6%). No statistical difference was observed in the incidence of coronary artery abnormalities (CAAs) between two groups either in the acute phase or follow-up phase.Higher use of adjuvant corticosteroids during initial therapy in our population may result in no difference in CAAs between the two groups despite higher levels of inflammation in KD-PI. Those results suggest that use of adjuvant corticosteroids may be beneficial in this population.