Infectious mononucleosis complicated with Kawasaki disease: Two case reports and literature review

ABSTRACT Introduction Infectious mononucleosis (IM) and Kawasaki disease (KD) can present with overlapping clinical features, occasionally complicating the differential diagnosis. Given the significant differences in their management, accurate distinction is critical. It is exceptionally rare for a single patient to simultaneously suffer from both IM and KD in clinical practice. Case presentation We report two cases of children over five years of age who initially presented with clinical manifestations suggestive of IM and serological evidence consistent with primary Epstein‐Barr virus (EBV) infection, supporting an initial diagnosis of IM. Subsequently, both patients developed clinical features meeting the diagnostic criteria for KD. The final diagnosis was co‐occurrence of IM and KD. Conclusion We describe two cases of concurrent IM and KD, offering further insight into a possible association between primary EBV infection and KD. Clinicians should be mindful of the potential co‐occurrence of these disorders, strive to avoid conflicts in treatment strategies, and take proactive measures to prevent complications.