Pseudomans aeruginosa and Staphylococcus aureus are the most common causes
Can sometimes be fungal (usually in immunocompromised individuals following prolonged antibiotic use) most commonly Candida or Aspergillus
Prevalence
Peak incidence is children aged 7-12 years
More common in summer months when swimming is more common
Prevention
Recurrence be prevented by keeping the external ear canal free of water using earlplugs or a shower or bathing cap during showering and swimming and acetic acid plus isopropyl alcohol ear drops following exposure to water
Presentation
Often follows water exposure and maceration of the skin
Tenderness on manipulation of the tragus or auricle and discharge may be present
Might be associated with regional lymphadenitis or cellulitis of the pinna and adjacent skin in serious cases
The ear canal may be erythematous and dry, or it may have grey or black fungal plaques that resemble fuzzy cotton wool
It is most commonly moist and oedematous, and the narrowed ear canal is filled with serous or purulent debris
Cerumen (ear wax) is characteristically absent
Patient with diabetes or immune compromise are susceptible to otomyocsis and necrotising otitis externa → evaluate more carefully
Management
Symptomatic
Analgesia (paracetamol or ibuprofen)
Non-Pharm
Keep external ear as dry as possible
Soft wax earplugs when showering
No swimming
Discharge or other debris should be removed from the ear canal by dry aural toilet (not syringing with water)
Healthcare professional: mechanical suction under direct visualisation, cotton wool on probe
Parent or carer: Dry mopping of the ear with the rolled up corner of tissue 6 hourly until dry
Pharm
Ear drops after performing dry aural toilet
After ear drops apply gentle presure to the tragus for 30 seconds
Bacterial:
Dexamethasone+framycetin+gramicidin ear drops, 3 drops instilled into the affected ear, 3 times daily for 7 days (Sofradex®, Otodex®)
If perforated tympanic membrane or tympanostomy tube in situ consider non-aminoglycysoide containing ear drops:
Ciprofloxacin+hydrocortisone ear drops 3 drops instilled into the affected ear, twice daily for 7 days
Fungal
Flumetasone+clioquinol 3 drops instilled into the affected ear twice daily for 7 days (Kenacomb otic ®/Otocomb Otic ®)
If fever and spread of inflammation to the pinna or folliculitis or immune compromise (including diabetes):
Obtain swabs
Add oral antibiotics:
Dicloxacillin 500mg 6 hourly for 7-10 days or flucloxacillin 500mg 6 hourly for 7-10 days PO
Ciprofloxacin 750mg 12 hourly for 7-10 days PO
Acute Localised Otitis Externa Management
Commonly caused by Staphylococcus aureus and associated with a boil or furuncle
Streptococcus pyogenes causes erysipelas that invovles the pinna and external canal
Manage with:
Dicloxacillin 500mg PO 6 hourly for 5 days or flucloxacillin 500mg PO 6 hourly for 5 days
In children consider cefalexin (tastes better): cefalexin 500mg (children: 12.5mg/kg up to 500mg) PO 6 hourly for 5 days
Necrotising Otitis Externa Management
Mostly in diabetes, elderly or immunocompromised patients
Spread of infection to cartilage and bone in the external ear canal and base of skull
Symptoms include fever, severe persistent pain, visible granulation tissue and progressive cranial neuropathies
Management
Refer urgently to infectious disease and ENT
Obtain superficial swabs or samples of tissue and pus for culture and susceptibility
Start empirical antibitoics until susceptibility testing results available:
Ceftazidime 2g IV 8 hourly or Piperacillin+Tazobactam 4+0.5g IV 6 hourly