Temporal Bone - EAC - Infectious/Inflammatory

Question 1

Necrotizing External Otitis

Answer 1

• AKA Malignant otitis externa
• Severe invasive infection of EAC, adjacent soft tissues, and skull base
• Swollen EAC soft tissues with bony erosion
• Osteomyelitis = Low T1 signal in bony marrow
• Phlegmon: Heterogeneously enhancing tissue
• Abscesses: Rim-enhancing fluid collections
• Look carefully for intracranial complications!! (increase mortality!!!): Venous sinus thrombosis, Meningitis, brain abscess, empyema
• Nuclear med: If bone scan and gallium scan both positive and gallium larger area, high correlation with necrotizing external otitis
• Usually seen with Diabetic vasculopathy and immune dysfunction
• Severe otalgia and otorrhea (*but can be “silent” disease if diabetic microangiopathy)
• Pseudomonas aeruginosa: 98%
• EAC SCC can look exactly like this; need to distinguish clinically (look in ear!)