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")
- 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
- 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.
- 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
- 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
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,
- 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
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