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Otitis externa - Background information
What is otitis externa?
- Otitis externa is inflammation of the external ear canal.
- Localized otitis externa is a folliculitis (infection of a hair follicle) that can progress to become a furuncle (boil) in the ear canal.
- Diffuse otitis externa is more widespread inflammation of the skin and subdermis of the external ear canal.
- It can extend to the external ear and the tympanic membrane (ear drum).
- It is also known as swimmer's ear, or tropical ear.
- Otitis externa is defined as:
- Acute if it has lasted less than 3 weeks.
- Chronic if it has lasted more than 3 months.
- Malignant otitis externa is an extension of otitis externa into the bone surrounding the ear canal (i.e. the mastoid and temporal bones). Because its most important feature is osteitis (bone infection), it is also known as malignant otitis (the term used elsewhere in this CKS topic) or necrotizing otitis.
[American Academy of Otolaryngology et al, 2006]
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