Otorrhoea Flashcards
What is otorrhoea?
Otorrhoea (discharging ear) is inflammation or infection of the middle ear (otitis media) or outer ear (otitis externa). It often occurs with pain (otalgia), hearing loss, tinnitus and sometimes vestibular disturbance.
What are the symptoms of otitis externa?
- Swelling of external ear canal, pulling on tragus can exacerbate pain
- Discharge, itching, conductive hearing loss
- Purulent debris and moist ear canal
- Usually a swimmer or uses cotton buds
What protects the outer ear from infection?
- Shape of external auditory canal (deep and tortuous)
- Wax (cerumen): lubricates skin, assists in clearance of debris and provides protection against bacteria, fungi, foreign bodies, water
- Hair: provides barrier to entry of foreign bodies into ear canal
- Skin: desquamates laterally out from tympanic membrane
What are risk factors for otitis externa?
- Allowing water to enter the ear
- Skin conditions i.e. eczema and psoriasis - these cause breaks in skin and make the ear canal itchy, often encouraging instrumentation of the ear
- Instrumentation of the ear canal with e.g. cotton buds which traumatise the ear canal and predispose to infection
What are investigations for otitis externa?
- Examine ear with otoscope
- Examine opposite ear for bilateral pathology
- Assess cranial nerves: can cause inflammation and weakness of facial nerve and other CNs
- In immunosuppressed, ear canal skin infection can spread to underlying bone and cause a more serious osteomyelitis of temporal bone
- Neck exam: look for any cervical lymphadenopathy
What are the causes for otitis externa?
- Staph. aureus (most common)
- Pseudomonas aeriguinosa (common cause of antibiotic drop resistant infection)
- Aspergillus niger (commonest fungal cause, not as common as bacterial causes)
What are the features of aspergillus niger otitis media?
- Tends to cause itching more than otalgia and otorrhoea is rare
- May develop as result of prolonged antibiotic use
- Often looks like a ball of cotton wool in the ear that is speckled with black dots (fungal spores)
- Treated with clotrimazole (antifungal)
What is the spread of infection in otitis externa?
- Minor skin trauma from foreign bodies or skin conditions allow bacteria in the ear or from water to access the subdermal layer»_space; inflammation
- Swelling, itching and watery discharge occur
- Infection spreads and patient develops otalgia and ear is tender to touch, discharge may become purulent
- Occasionally, the pre- and post-auricular lymph nodes may swell thus mimicking acute mastoiditis (post auricular sulcus intact)
- Infection may spread to involve the cartilage (perichondritis) or skin surrounding the ear (cellulitis)
What is the risk in diabetic/immunocompromised patients with otitis externa?
Infection can spread to involve the bone of skull base. This is a form of osteomyelitis and is commonly called malignant otitis externa (no neoplastic process) or necrotising otitis externa. This can affect the inner ear also (cause sensorineural deafness) and is potentially life-threatening. High index of suspicion in these patients if symptoms don’t settle within 2 weeks - pain out of proportion to presentation and not responding to abx.
What is the treatment for otitis externa?
- Usually self-limiting
- Oral analgesia (always assess pain)
- Keep ear dry
- Topical antibiotic drop with steroid (take swab prior to commencing abx to identify bacteria and abx sensitivity)
- Consider oral antibiotic (flucloxacillin) if infection spreading
- Oral ciprofloxacin for otitis externa in diabetics (best against pseudomonas)
What are examples of antibiotic drops containing steroid?
Typically given for 7-10 days:
- Sofradex (Framycetin, dexamethasone + gramicidin) - 2-3 drops, 3-4x a day
- Gentisone H/C (Gentamicin 0.3% and hydrocortisone 1%) - 2-4 drops, 4-5x a day
- Otomize (dexamethasone, neomycin and acetic acid) - also used in mild cases
- Sometimes topical ciprofloxacin drops (not licensed in UK)
What is complication of untreated otitis externa?
Perichondritis (cartilage inflammation - pseudomonas) of pinna - can also get from trauma to the pinna. If left untreated can cause pinna cartilage necrosis (causes pinna deformity) leading to ‘cauliflower ear’.
Causes: infection, trauma, eczema, piercings, insect bite
What is the management of pinna perichondritis?
- Gentle micro-suction of ear: remove infected debris (can be painful and difficult)
- Continue topic drops with insertion of aural wick (topical antibiotics are very important so to achieve this might need to stent open ear canal with an otowick/aural tampon) - swells once contact with antibiotic drops to allow entry, usually stays for 48 hours
- Admit and commence IV antibiotics if they show signs of systemic illness e.g. fever
- Re-assessment in outpatient clinic 4 weeks after treatment period to assess hearing and recovery
What are the complications of acute otitis externa?
Early:
- Facial cellulitis: can develop if infection spreads to facial skin
- Otomycosis: can occur following use of topical anti-bacterial agent
Late:
- Canal stenosis with hearing loss
What is the treatment for osteomyelitis?
- Use topical antibiotics
- IV antibiotics are ESSENTIAL for at least 6 weeks - via in dwelling catheter and patient can go home, if well enough, and have treatment in community
- Regular clinical assessments and blood tests for CRP/ESR and MRI skull base to monitor progress
- Organism usually pseudomonas aeruginosa but take swabs first to confirm
What are the symptoms and treatment of mastoiditis?
- Symptoms: severe pain and redness behind ear, swelling causes ear to stick out, patient would be systemically unwell (fever)
- Tx: IV abx and may need drainage of middle ear via surgery
What questions do you want to ask in a history for otitis media?
- Duration of symptoms
- Any otalgia
- Is there any discharge (otorrhoea) and is this thick, watery, offensive?
- Is there any associated hearing loss (how does this affect the patient)?
- Are there any problems with balance?
- Is there any tinnitus?
- What treatment have they had so far and has it responded?
- What hobbies/sports do they do e.g. swimming?
- Have they had surgery to the affected ear?
- Do they have any other significant medical problems e.g. allergic chronic rhinosinusitis, asthma, diabetes?
Which part of the tympanic membrane is most likely to be perforated?
Pars tensa - also a white plaque can form here caused by calcium deposition within the membrane from healing of previous ear infections, this is called tympanosclerosis. This can sometimes be mistaken for a cholesteatoma.
