To carry out a review of clinical characteristics, laboratory profiles, management and outcomes of patients with Kawasaki disease (KD) and macrophage activation syndrome (MAS).
Medical records of patients treated for KD and MAS between January 1994 and December 2019 were reviewed. Patient demographics, clinical signs, laboratory values, coronary artery abnormalities, treatments and outcomes of patients with KD and MAS were recorded. We also performed a review published studies on the subject.
Of the 950 cases with KD, 12 (1.3%; 10 boys, 2 girls) were diagnosed with MAS. The median age at diagnosis was 4 years (range 9 months-7.5 years). The median interval between onset of fever and diagnosis of KD was 11 days (range 6-30). Thrombocytopenia was seen in 11 patients. The median pro-brain natriuretic peptide value was 2101 pg/ml (range 164-75 911). Coronary artery abnormalities were seen in 5 (41.7%) patients; 2 had dilatation of the left main coronary artery (LMCA), 1 had dilatation of both the LMCA and right coronary artery (RCA), 1 had dilatation of the RCA and 1 had bright coronary arteries. All patients received IVIG as first-line therapy for KD. MAS was treated with i.v. methylprednisolone pulses followed by tapering doses of oral prednisolone. Additional therapy included i.v. infliximab (n = 4), second-dose IVIG (n = 1) and oral ciclosporin (n = 1).
MAS is an unusual and underrecognized complication of KD. In our cohort of 950 patients with KD, 1.3% had developed MAS. KD with MAS is associated with an increased propensity towards development of coronary artery abnormalities.