Abstract
DEFINITION
Otitis externa is a generalized condition of the skin of the external auditory canal. It is characterized by oedema and erythema associated with itch, pain and discharge.
CLASSIFICATION
There is no universally accepted classification for otitis externa and it has been put into many subcategories in the past. In fact, most of these (e.g. eczematous otitis externa) are actually just predisposing factors.
PATHOLOGY
The clinical course of diffuse otitis externa is extremely variable but has been divided into the following stages:
Stage 1: Pre-inflammatory
Stage 2: Acute inflammatory (mild, moderate or severe)
Stage 3: Chronic inflammatory
In stage 1, the protective lipid/acid balance (normal pH 4–5) of the ear is lost and the stratum corneum becomes oedematous, blocking off the sebaceous and apocrine glands and producing aural fullness and itching. With further oedema and scratching, there is disruption of the epithelial layer and invasion of resident or introduced organisms. This results in stage 2, with a progressively thickening exudate, further oedema, obliteration of the lumen (mild: little or no obliteration; moderate: sub-total obliteration; severe: complete obliteration) and increasing pain. In the severe stages, auricular changes and cervical lymphadenopathy are often seen. After 6 months, by definition, chronic otitis externa occurs. Stage 3 is characterized by thickening of the external canal skin and this is covered in Chapter 77, Acquired atresia of the external ear...
Otitis externa is a generalized condition of the skin of the external auditory canal. It is characterized by oedema and erythema associated with itch, pain and discharge.
CLASSIFICATION
There is no universally accepted classification for otitis externa and it has been put into many subcategories in the past. In fact, most of these (e.g. eczematous otitis externa) are actually just predisposing factors.
PATHOLOGY
The clinical course of diffuse otitis externa is extremely variable but has been divided into the following stages:
Stage 1: Pre-inflammatory
Stage 2: Acute inflammatory (mild, moderate or severe)
Stage 3: Chronic inflammatory
In stage 1, the protective lipid/acid balance (normal pH 4–5) of the ear is lost and the stratum corneum becomes oedematous, blocking off the sebaceous and apocrine glands and producing aural fullness and itching. With further oedema and scratching, there is disruption of the epithelial layer and invasion of resident or introduced organisms. This results in stage 2, with a progressively thickening exudate, further oedema, obliteration of the lumen (mild: little or no obliteration; moderate: sub-total obliteration; severe: complete obliteration) and increasing pain. In the severe stages, auricular changes and cervical lymphadenopathy are often seen. After 6 months, by definition, chronic otitis externa occurs. Stage 3 is characterized by thickening of the external canal skin and this is covered in Chapter 77, Acquired atresia of the external ear...
| Original language | English |
|---|---|
| Title of host publication | Scott-Brown's Otorhinolaryngology and Head and Neck Surgery |
| Subtitle of host publication | Paediatrics, The Ear, and Skull Base Surgery |
| Editors | John C. Watkinson, Raymond W. Clarke |
| Publisher | CRC Press/Balkema |
| Chapter | 78 |
| Pages | 953-958 |
| Number of pages | 6 |
| Volume | 2 |
| Edition | 8th |
| ISBN (Print) | 978-1-138-09463-4, 9781444175899 |
| Publication status | Published - 12 Jun 2018 |
Keywords
- Otitis externa
- Otomycosis