clinical features
Last edited 04/2021 and last reviewed 04/2021
The principal complaint is that of irritation (1).
Other symptoms may include:
- symptoms are of rapid onset (generally within 48 hours) (3)
- scanty discharge - there are no mucous secreting glands in the external ear; profuse discharge suggests middle ear disease
- bacterial infection
- typically associated with scant white purulent discharge, which occasionally can be thick (2)
- fungal discharge
- otomycosis, or fungal infection of the external ear canal, is common in tropical countries, humid locations, after longterm topical antibiotic therapy, and in those with diabetes, HIV infection, or an immunocompromised state
- fungal otitis externa
should also be suspected if a patient fails to respond to initial
topical therapy
- Aspergillus
species (60%-90%) and Candida species (10%-40%) are often
cultured (3)
- possible symptoms include pruritus and thickened otorrhea, which may be black, gray, bluish green, yellow, or white
- candidal otitis externa generally results in white debris
- Aspergillus niger usually appears as a moist white plug dotted with black debris ("wet newspaper")
- Aspergillus
species (60%-90%) and Candida species (10%-40%) are often
cultured (3)
- bacterial infection
- otalgia
- present in 70% of people with acute otitis externa (3)
- however, deep severe pain that is out of proportion to the general presentation of the patient should alert you to the possibility of malignant otitis externa
- present in 70% of people with acute otitis externa (3)
- itching (60%) (3)
- feeling of fullness (22%), with or without hearing loss (32%) (3)
- hearing loss if present is mild
- ear canal pain on chewing
Examination reveals:
- may reveal meatal tenderness - often, marked
- may be tenderness
of the tragus (when pushed), the pinna (when pulled),
or both (3)
- tenderness is often intense and disproportionate to what might be expected based on appearance of the ear canal on inspection.
- may be tenderness
of the tragus (when pushed), the pinna (when pulled),
or both (3)
- narrowed, oedematous meatus
- meatal debris
- erythema and swelling
- primarily affecting the pinna
- simple pinna cellulitis will typically involve the ear lobe (2)
- however sparing of the ear lobe
may indicate perichondritis
- if perichondritis is suspected then requires same day ENT opinion as urgent intravenous antibiotics may be indicated to prevent sepsis and long term deformity from destruction of the cartilage
- primarily affecting the pinna
- examine the mastoid area for erythema, swelling, and tenderness
- tenderness over this area is common in otitis externa (2)
- however if
the patient has associated bogginess/fluctuance, loss of the
post-auricular sulcus, or protrusion of the pinna, then the clinician should suspect possible mastoiditis and therefore same day ENT review is indicated
- however if
the patient has associated bogginess/fluctuance, loss of the
post-auricular sulcus, or protrusion of the pinna, then the clinician should suspect possible mastoiditis and therefore same day ENT review is indicated
- tenderness over this area is common in otitis externa (2)
Tuning fork tests may demonstrate mild conductive deafness
Summary (3):
- elements of the diagnosis of diffuse acute otitis externa
- 1. Rapid onset (generally within 48 hours) in the past 3 weeks,
- AND…
- 2. Symptoms of ear canal inflammation, which include:
- otalgia (often severe), itching, or fullness,
- WITH OR WITHOUT hearing loss or jaw pain,
- AND…
- 3. Signs of ear canal inflammation, which include:
- tenderness of the tragus, pinna, or both
- OR diffuse ear canal edema, erythema, or both
- WITH OR WITHOUT otorrhea, regional lymphadenitis, tympanic membrane erythema, or cellulitis of the pinna and adjacent skin
- 1. Rapid onset (generally within 48 hours) in the past 3 weeks,
Notes:
- AOE can mimic the appearance of acute otitis media
(AOM) because of erythema involving the tympanic membrane (3)
- distinguishing AOE from AOM is important, because the latter may require systemic antimicrobials
- tinnitus (2)
- is rarely seen in isolation with otitis externa
- a conductive hearing loss caused by ear canal oedema may worsen pre-existing tinnitus
- acute otitis externa can mimic the appearance of acute otitis media (AOM) because of erythema involving the tympanic membrane (3)
Reference:
- Sander R. Otitis Externa: A Practical Guide to Treatment and Prevention.Am Fam Physician 2001;63:927-36,941-2.
- Barry V et al. 10-Minute Consultation - Otitis externa. BMJ2021;372:n714http://dx.doi.org/10.1136/bmj.n714
- Rosenfeld RM, Schwartz SR, Cannon CR, et al. Clinical practice guideline: acute otitis externa.Otolaryngol Head Neck Surg2014;150(Suppl):S1-24.doi: 10.1177/0194599813517083