The diagnostic conundrum in necrotizing otitis externa

Abstract

Necrotizing otitis externa (NOE) is an aggressive and fast-evolving infection of the external auditory canal. Late diagnoses and untreated cases can lead to severe, even fatal consequences and so early diagnosis and treatment are paramount. NOE is a notoriously challenging diagnosis to make. It is therefore important to understand what diagnostic modalities are available and how otolaryngologists can use them to accurately treat such an aggressive disease. This review aims to evaluate the different diagnostic options available in NOE and discuss their advantages and limitations, thus, providing an up-to-date picture of the multimodal approach required in the diagnosis of this disease.

Keywords: diagnostic; malignant otitis externa; necrotizing; osteomyelitis; skull base osteomyelitis; temporal bone osteomyelitis.

Figure 1

Axial computed tomography (CT) scan of the temporal bones and head showing focal bone destruction of the anterior aspect of the external auditory canal (arrow). There is also extensive opacification of the right mastoid air system.

Figure 2

Axial magnetic resonance (MR) scan of the head with gadolinium enhancement demonstrating changes consistent with left necrotizing otitis externa (NOE) and extension into the masticator space (labeled masticator) and temporomandibular joint (labeled TMJ). There is extensive thickening and opacification of the external auditory canal (EAC) and mastoid opacification.