	'swimmer's ear'
Etiology	Acute: Commonly caused by Staph aureus or Pseudomonas. In chronic form (>3/12), candida or aspergillus commonly implicated.
Epidemiology	Risk factors: damage to skin barrier - eczema, psoriasis etc.
Clinical presentation	Rapid onset (48h) - erythematous ear canal, debris, signs of fungal infection - At least 2 of: - Tenderness of the tragus and/or pinna. - red and oedematous ear canal +/- debris and ear discharge - Tympanic membrane erythema - Cellulitis of the pinna and adjacent skin - Conductive hearing loss (less common). - Tender regional lymphadenitis (less common).
Pathogenesis
Diagnostic investigations
Management	Hygiene - keep clean and dry e.g. ear plugs when showering Topical abx + steroid drops ➥ avoid gentamicin if any suspicion of perforated TM - risk ototoxicity e.g. Ciprofloxacin 0.3%, dexamethasone 0.1% ear drops or sofradex

malignant otitis externa

or 'necrotising otitis'

clinical presentation red flags

Granulation tissue seen on the floor of the ear canal and at the bone-cartilage junction; exposed bone in the ear canal.
Ipsilateral facial nerve palsy.
- Unremitting disproportionate ear pain, headache, purulent otorrhoea, fever, or malaise.
Vertigo.
Profound conductive hearing loss.