Internal carotid artery arteritis as a rare complication of pediatric otomastoiditis: serial magnetic resonance imaging and magnetic resonance angiography findings.

Acute otomastoiditis is a common pediatric infection that may rarely lead to severe intracranial complications. The frequency of otomastoiditis, and even more so the frequency of intracranial complications, significantly increased after the end of the coronavirus disease 19 pandemic. We report a 14-month-old boy with bilateral otomastoiditis complicated by extensive venous sinus thrombosis, petrous apicitis, and progressive infectious arteritis of the cavernous internal carotid artery. Serial magnetic resonance imaging and magnetic resonance angiography demonstrated interval internal carotid artery narrowing with vessel wall enhancement, subsequent arterial occlusion, and focal ischemic injury. Despite these findings, the patient remained neurologically intact and showed radiologic improvement at follow-up. This case highlights a rare arterial complication of pediatric otomastoiditis and underscores the importance of comprehensive and serial vascular imaging for early detection, differentiation from extrinsic compression, and guidance of multidisciplinary management.