Kawasaki disease associated with Mycoplasma pneumoniae

Background Kawasaki disease (KD) is an illness of unknown etiology that mostly occurs in children under 5 years of age and is the leading cause of acquired heart disease all over the world. Mycoplasma pneumoniae (MP) was one of the likely causative agents of KD. However, the etiologic effect of MP in KD has not been fully recognized. Methods We prospectively analyzed the clinical records of 450 patients with KD hospitalized in Children’s Hospital of Soochow University from 2012 to 2014. Using medical records, we retrospectively identified patients with low respiratory tract infection (non-KD group). Results Of the 450 KD patients, MP was positive in 62 (13.8 %). The median age of the MP + KD+ group was significantly older than the MP-KD+ group (25 vs 14.5 months, P < 0.01). MP + KD+ group had higher levels of ESR, N% and CRP than the MP-KD+ group. MP + KD+ group were more frequent in respiratory disorders than MP-KD+ group with a P < 0.05. No statistical difference of non-responders or coronary artery lesion was found between the groups. Conclusions MP infections are found in an important proportion of the KD patients (13.8 % in our series). MP infection tended to occur in older populations and with a higher rate of respiratory tract involvement in patients with KD. No statistical difference of non-responders or coronary artery lesion was found between the MP+ and MP- KD patients.