Mycoplasma encephalitis, incomplete Kawasaki disease and MERS, a new association? Short communication

BACKGROUND: Mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) is an uncommon clinico-radiological entity, mostly described in children in association with viral or atypical bacterial infections. Mycoplasma pneumoniae (MP) is a rare but recognized trigger. Kawasaki disease (KD) may also present with neurological involvement. OBSERVATION AND DISCUSSION: We report the case of a 14-year-old boy with acute encephalopathy, Mycoplasma pneumoniae infection, and features of incomplete KD. Brain MRI showed a reversible lesion in the splenium of the corpus callosum consistent with MERS. The patient developed mucocutaneous signs and transient coronary artery dilatation. He improved with antibiotic and anti-inflammatory therapy. CONCLUSION: This case highlights a rare overlap between MERS, Mycoplasma pneumoniae, and incomplete KD, suggesting shared inflammatory pathways. Clinicians should consider this association when encountering pediatric encephalopathy with systemic inflammatory features.