Skull Base Osteomyelitis Complicated by Petrous Internal Carotid Artery Blowout.

Skull base osteomyelitis (SBO) is an invasive infection of the external auditory canal, with involvement of the skull base, typically in the elderly diabetic population. Diagnosis may be challenging, as it requires a combination of clinical, laboratory, and radiographical findings. The mainstay of treatment is long-term antibiotic therapy, but surgical debridement of the temporal bone may be necessary in refractory cases. Commonly reported complications include cranial neuropathies, meningitis, temporal lobe abscess, and dural venous sinus thrombosis. A rare and life-threatening complication of SBO is petrous internal carotid artery (ICA) blowout, which has been described as presenting with bleeding from the ear. Here, we describe the case of a 77-year-old woman with SBO complicated by a petrous ICA blowout, which presented with fulminant epistaxis. To our knowledge, this is the second reported case of a massive hemorrhage from a petrous ICA blowout secondary to SBO and the first presentation with massive epistaxis. We present this case to raise awareness of this potential impending complication in patients with SBO and recommend consideration of this etiology when assessing patients with massive epistaxis in the appropriate clinical setting. Level of evidence: III.