Background Kawasaki disease (KD), or mucocutaneous syndrome, is the leading cause of childhood-acquired heart disease in high-income countries. There is much controversy on how best to treat children with KD and in particular who may benefit from additional treatment beyond the standard intravenous immunoglobulin (IVIG) and aspirin, such as the addition of corticosteroids. This is an update of the review first published in 2017. Objectives To assess the impact of corticosteroid use on the incidence of coronary artery abnormalities in KD as either first-line or second-line treatment. Search methods The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL and two trials registers to 8 February 2021. We searched the reference lists of relevant articles for additional studies. Selection criteria We selected randomised controlled trials involving children with all severities of KD who were treated with corticosteroids, including different types of corticosteroids, different durations of treatment, and where corticosteroids were used alone or in conjunction with other accepted KD treatments. We included trials using corticosteroids for both first- and second-line treatment. Data collection and analysis Two review authors independently selected studies, assessed study quality and extracted data using standard Cochrane methods. We performed fixed-effect model meta-analyses with odds ratios (ORs) or mean difference (MD) with 95% confidence intervals (Cis). We used a random-effects model when there was heterogeneity. We assessed the certainty of the evidence using GRADE. The outcomes of interest were incidence of coronary artery abnormalities, serious adverse events, mortality, duration of acute symptoms (such as fever), time for laboratory parameters to normalise, length of hospital stay and longer-term coronary morbidity. Main results This update identified one new study, therefore the analysis included eight trials consisting of 1877 participants. Seven trials investigated the use of corticosteroids in first-line treatment and one investigated second-line treatment. The trials were all of good methodological quality. On pooled analysis, corticosteroid treatment reduced the subsequent occurrence of coronary artery abnormalities (OR 0.32, 95% CI 0.14 to 0.75; 8 studies, 986 participants; moderate-certainty evidence), without resultant serious adverse events (0 events; 6 studies, 737 participants; moderate-certainty) and mortality (0 events; 8 studies, 1075 participants; moderate-certainty evidence). In addition, corticosteroids reduced the duration of fever (MD -1.34 days, 95% CI -2.24 to -0.45; 3 studies, 290 participants; low-certainty evidence), time for laboratory parameters (erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP)) to normalise (MD -2.80 days, 95% CI -4.38 to -1.22; 1 study, 178 participants; moderate-certainty evidence), and length of hospital stay (MD -1.01 days, 95% CI -1.72 to -0.30; 2 studies, 119 participants; moderate-certainty evidence). None of the included studies reported long-term (greater than one year after disease onset) coronary morbidity. Authors' conclusions Moderate-certainty evidence shows that use of steroids in the acute phase of KD can be associated with reduced coronary artery abnormalities, reduced inflammatory markers and shorter duration of hospital stay when compared to no corticosteroids. There were no serious adverse events or deaths reported with or without corticosteroid use. Low-certainty evidence shows use of corticosteroids can reduce duration of clinical symptoms (fever and rash). None of the included studies reported on long-term (greater than one year after disease onset) coronary morbidity. Evidence presented in this systematic review agrees with current clinical guidelines on the use of corticosteroids in the first-line treatment in KD.
