32 OTOLARYNGOLOGY
# 33 OTOLARYNGOLOGY
ENT comes up reliably in MRCS Part A because it sits at the crossroads of head and neck anatomy, embryology, microbiology and acute surgical management. This chapter teaches the topic the way examiners test it: anatomy first, then the conditions, then the SBAs.
Detailed notes
Anatomy of the ear
The ear is divided into three functional compartments. Knowing what lives in each compartment lets you predict the clinical picture from the lesion's location.
- Outer ear — auricle, external acoustic meatus (EAM) and lateral surface of the tympanic membrane (TM). Lined by skin. Disease here is dermatological: otitis externa, wax, foreign body.
- Middle ear — an air-filled cavity in the petrous temporal bone, housing the three ossicles (malleus, incus, stapes) and connected to the nasopharynx via the Eustachian tube and to the mastoid air cells posteriorly. Disease here is infective/effusive: otitis media, mastoiditis, cholesteatoma.
- Inner ear — the bony and membranous labyrinth (cochlea + vestibular apparatus), filled with endolymph and perilymph. Disease here is sensorineural: Meniere's, vestibular schwannoma, presbycusis.
Sensory innervation of the auricle is a classic SBA. Each region is supplied by a different nerve:
| Region | Nerve | Root |
|---|---|---|
| Tragus, anterior auricle, EAM, TMJ | Auriculotemporal | V3 |
| Most of auricle, mastoid, angle of mandible, parotid skin | Greater auricular | C2, C3 |
| Postauricular scalp, upper neck | Lesser occipital | C2 |
| Posterior scalp to vertex | Greater occipital | C2 |
| Middle ear mucosa | Tympanic plexus | CN IX (glossopharyngeal) |
👩⚕️ Referred otalgia: pain in a "normal" ear often comes from CN V, VII, IX or X distributions — think tonsil cancer, laryngeal tumour, dental disease.
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Outer ear disease
Otitis externa ("swimmer's ear") is infection of the EAM skin, typically Pseudomonas or Staph aureus. Presents with itch, tragal tenderness on pulling the pinna, and discharge. Treat with topical antibiotic–steroid drops and aural toilet. Malignant (necrotising) otitis externa is the dangerous variant: an elderly diabetic or immunocompromised patient with severe pain, granulation tissue in the EAM and risk of osteomyelitis of the skull base — needs IV antibiotics.
Middle ear disease
Acute otitis media (AOM) — viral URTI causes Eustachian tube dysfunction, fluid accumulates, then bacterial superinfection (Strep pneumoniae, H. influenzae, Moraxella). The TM becomes red and bulging. Most resolve without antibiotics; give amoxicillin if systemically unwell or symptoms persist beyond 3 days.
TM perforation — usually from AOM (relieves pain as pus escapes) or barotrauma. Most heal spontaneously within 6 weeks. Keep the ear dry.
Mastoiditis is the feared complication of AOM: infection spreads from the middle ear into the mastoid air cells, producing fever, postauricular swelling that pushes the pinna forwards, and erythema over the mastoid. Untreated it can erode into the posterior cranial fossa producing cerebellar abscess (ataxia + fever after recent otitis), meningitis or sigmoid sinus thrombosis. Treat with IV antibiotics ± cortical mastoidectomy.
Cholesteatoma — a sac of keratinising squamous epithelium that grows into the middle ear, classically through a pars flaccida retraction pocket. It is locally destructive: it erodes ossicles (conductive hearing loss), facial canal (CN VII palsy) and bone. Classic exam picture is chronic foul-smelling ear discharge + conductive hearing loss ± facial nerve palsy. Treatment is surgical (mastoidectomy).
Inner ear disease
Meniere's disease — episodic vertigo (lasting hours), fluctuating sensorineural hearing loss, tinnitus and aural fullness, caused by endolymphatic hydrops. Manage with low-salt diet, betahistine and vestibular sedatives during attacks.
Vestibular schwannoma (acoustic neuroma) — benign schwannoma of CN VIII at the cerebellopontine angle. Unilateral progressive sensorineural hearing loss + tinnitus ± facial numbness (CN V) as it enlarges. Bilateral schwannomas = neurofibromatosis type 2. Diagnosis by MRI internal auditory meatus.
Hearing loss: conductive vs sensorineural
This is examined every sitting. Master the two tuning-fork tests.
| Weber (512 Hz on forehead) | Rinne (mastoid vs EAM) | |
|---|---|---|
| Normal | Central | AC > BC (positive) |
| Conductive loss | Lateralises to affected ear | BC > AC on affected side (negative) |
| Sensorineural loss | Lateralises to unaffected ear | AC > BC bilaterally (positive both sides) |
👩⚕️ Logic for Weber: in conductive loss the blocked ear hears the bone-conducted sound without the masking effect of background air noise, so it sounds louder there. In sensorineural loss the cochlea is dead — sound localises to the good side.
Causes
- Conductive: wax, otitis externa, AOM with effusion, TM perforation, otosclerosis, cholesteatoma.
- Sensorineural: presbycusis, noise-induced, ototoxicity (gentamicin, cisplatin, loop diuretics), Meniere's, vestibular schwannoma.
Nasal cavity and epistaxis
The nasal septum has a rich anastomotic blood supply called Kiesselbach's plexus in Little's area (antero-inferior septum). It is fed by branches of both internal and external carotid arteries:
- Sphenopalatine artery — terminal branch of maxillary (ECA)
- Greater palatine artery — maxillary (ECA)
- Superior labial artery — facial (ECA)
- Anterior ethmoidal artery — ophthalmic (ICA)
90% of epistaxis is anterior from Little's area — easy to compress, easy to cauterise. Posterior epistaxis arises from the sphenopalatine artery deeper in the cavity and is more dangerous: blood streams down the throat, the source is invisible, and bleeding is harder to control.
Management ladder
1. First aid: lean forward, pinch the cartilaginous (soft) part of the nose for 15 minutes, ice on the bridge.
2. Topical vasoconstrictor (co-phenylcaine) + silver nitrate cautery to the visible bleeding point.
3. Anterior pack (nasal tampon, e.g. Rapid Rhino).
4. Posterior pack (Foley catheter balloon) — admit for airway risk.
5. Sphenopalatine artery ligation endoscopically, or radiological embolisation, for refractory bleeds.
👩⚕️ Examiners love asking which artery feeds Little's area. The single most-cauterised vessel is the sphenopalatine (branch of maxillary, branch of ECA).
Paranasal sinuses and sinusitis
Four pairs drain into the nose:
| Sinus | Drains into |
|---|---|
| Frontal | Middle meatus (via frontonasal duct) |
| Anterior + middle ethmoidal | Middle meatus |
| Maxillary | Middle meatus (via hiatus semilunaris) |
| Posterior ethmoidal | Superior meatus |
| Sphenoidal | Sphenoethmoidal recess |
The maxillary sinus is most commonly affected because its ostium sits high on the medial wall — gravity works against mucociliary clearance. Acute sinusitis follows a viral URTI, causing facial pain worse on bending forwards, purulent rhinorrhoea and a blocked nose. Most are viral; reserve antibiotics for severe or persistent (>10 day) cases.
Mucociliary clearance depends on coordinated cilia sweeping mucus toward the ostium. Smoking, Kartagener's (primary ciliary dyskinesia) and cystic fibrosis impair this and cause recurrent sinusitis and bronchiectasis.
Nasal polyps are pale, semi-translucent oedematous outgrowths of sinus mucosa. Samter's triad = asthma + aspirin sensitivity + nasal polyps. Bilateral polyps in a child should prompt a sweat test (CF).
Sinus tumours — adenocarcinoma of the ethmoid sinus is strongly associated with hard wood dust exposure (carpenters, furniture-makers). Nasopharyngeal carcinoma is an EBV-driven SCC, prevalent in East Asian and southern Chinese populations, classically presenting with unilateral epistaxis, conductive hearing loss (Eustachian tube blockage) and a neck node.
Throat: tonsillitis, quinsy
Tonsillitis is usually viral. Bacterial cause is Group A Strep (Streptococcus pyogenes). The Centor criteria predict bacterial cause — 3 or 4 of the following justify antibiotics:
- Cough absent
- Exudate on tonsils
- Nodes (tender anterior cervical)
- Temperature > 38 °C
- Age 3–14 (modified McIsaac scoring)
Treat with phenoxymethylpenicillin (avoid amoxicillin — causes a rash in EBV).
Quinsy (peritonsillar abscess) — usually a complication of bacterial tonsillitis. Fever, severe odynophagia, "hot potato" voice, trismus and uvular deviation away from the affected side. Treat with needle aspiration or incision and drainage + IV antibiotics.
Ludwig's angina — bilateral cellulitis of the submandibular space (usually from a lower molar infection). Brawny floor-of-mouth swelling pushes the tongue up, threatening the airway. Surgical emergency.
Sleep apnoea
Obstructive sleep apnoea (OSA) — repeated upper airway collapse during sleep. Risk factors: obesity, large neck circumference, retrognathia, tonsillar hypertrophy (in children). Presents with snoring, witnessed apnoeas, daytime somnolence (Epworth score). Diagnose with overnight polysomnography. First-line treatment is CPAP; weight loss helps. Untreated OSA increases cardiovascular and stroke risk and is a hazard in any anaesthetic.
Stridor by age
Stridor (high-pitched inspiratory noise) signals upper airway narrowing. Cause depends on age:
| Age | Most likely cause | Key features |
|---|---|---|
| Neonate | Laryngomalacia | Stridor worse on feeding/lying flat; self-resolves |
| 6 mo – 6 yr | Croup (parainfluenza) | Barking cough, low-grade fever, slow onset |
| 2 – 7 yr | Epiglottitis (H. influenzae B) | Drooling, tripod, toxic, fast onset — do not examine throat |
| Any age | Foreign body | Sudden onset, witnessed choking, unilateral wheeze |
| Adult | Anaphylaxis, tumour, post-extubation oedema | Context-dependent |
Hoarseness and the recurrent laryngeal nerve
The recurrent laryngeal nerve (RLN) supplies all intrinsic laryngeal muscles except cricothyroid (external branch of superior laryngeal). It loops under the right subclavian artery on the right and under the arch of aorta on the left, making the left RLN much longer and more vulnerable.
Causes of RLN palsy → hoarseness
- Lung cancer (especially left apical / Pancoast tumours stretching the left RLN)
- Thyroid surgery — the RLN runs in the tracheo-oesophageal groove, close to the inferior thyroid artery
- Aortic arch aneurysm (left RLN)
- Oesophageal cancer, mediastinal nodes
- Idiopathic / viral
Unilateral palsy = breathy hoarse voice. Bilateral palsy (e.g. after total thyroidectomy) = stridor and airway compromise because both cords sit in the paramedian position.
Salivary glands
Three paired major glands: parotid (serous), submandibular (mixed) and sublingual (mucinous). Examiners ask about three things: stones, infection, tumours.
Sialolithiasis affects the submandibular gland in 80% of cases because its secretion is mucinous and viscous, and Wharton's duct ascends against gravity. Classic picture: postprandial swelling and pain that settles between meals. Diagnose with US or sialography; remove transorally or by gland excision.
Sialadenitis — bacterial infection (Staph aureus) in a dehydrated post-op patient, or viral (mumps — bilateral parotid swelling).
Tumours — remember the percentages: 80% parotid, 80% benign, 80% pleomorphic adenoma.
| Tumour | Behaviour | Key fact |
|---|---|---|
| Pleomorphic adenoma | Benign, slow-growing | Most common parotid tumour; recurs if shelled out, needs superficial parotidectomy |
| Warthin's tumour | Benign, cystic | Smokers; bilateral in 10%; older men |
| Mucoepidermoid carcinoma | Malignant | Most common salivary malignancy overall |
| Adenoid cystic carcinoma | Malignant | Perineural invasion, late recurrence, often minor salivary glands; CN VII palsy on parotid mass |
| Lymphoma | Malignant | Lymphocytes only on FNA + lymphadenopathy → open biopsy |
👩⚕️ Submandibular masses behave the opposite way to parotid masses. Only ~8% of salivary tumours arise in the submandibular gland, but ~50% of those are malignant. All submandibular masses should be excised.
👩⚕️ Facial nerve palsy + parotid mass = malignancy until proven otherwise (most often adenoid cystic carcinoma).
Heerfordt syndrome (uveoparotid fever) = sarcoid with parotid swelling, uveitis, CN VII palsy and fever — steroid-responsive.
Sjögren's syndrome — autoimmune lymphocytic destruction of exocrine glands → dry eyes, dry mouth, bilateral parotid swelling, often with rheumatoid arthritis. No facial palsy.
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Test yourself
A man with epistaxis from Little's area is treated with direct cautery. Which artery is most likely responsible?
- ((Anterior ethmoidal::Contributes to Little's area but rarely the cauterised vessel; branch of ophthalmic (ICA).))
- ((Infraorbital::Supplies cheek skin and upper lip — not Little's area.))
- ((Sphenopalatine::☑️ Terminal branch of maxillary (ECA); the main feeder cauterised in anterior epistaxis.))
- ((Supratrochlear::Supplies medial forehead — not nasal cavity.))
👩⚕️ Little's area is fed by BOTH carotid systems — a favourite exam trap.
Which sinus drains into the superior meatus?
- ((Maxillary::Drains into the middle meatus via the hiatus semilunaris.))
- ((Frontal::Drains into the middle meatus via the frontonasal duct.))
- ((Posterior ethmoidal::☑️ The only sinus that drains into the superior meatus.))
- ((Sphenoid::Drains into the sphenoethmoidal recess, above the superior turbinate.))
Which nerve supplies cutaneous sensation over the angle of the mandible?
- ((Auriculotemporal::V3 — supplies temple, TMJ, EAM, tragus.))
- ((Greater auricular::☑️ C2–C3; angle of mandible, parotid skin, mastoid, most of auricle.))
- ((Buccal::V3 — supplies buccal mucosa and skin over cheek, not angle of mandible.))
- ((Mental::V3 — chin and lower lip only.))
👩⚕️ The angle of mandible spares V3 — useful clinically (e.g. preserved sensation here in a trigeminal lesion points elsewhere).
A patient with fever, odynophagia and uvular deviation. Diagnosis?
- ((Ludwig's angina::Submandibular space infection; floor-of-mouth swelling, no uvular deviation.))
- ((Acute tonsillitis::Bilateral inflamed tonsils, uvula central.))
- ((Quinsy::☑️ Peritonsillar abscess pushes the uvula to the opposite side; usually Strep pyogenes.))
- ((Oropharyngeal carcinoma::Chronic, non-febrile, painless mass.))
A patient has had ear discharge for 10 years, with TM perforation and now facial nerve palsy. Diagnosis?
- ((Chronic suppurative otitis media::Causes discharge but rarely erodes the facial canal.))
- ((Cholesteatoma::☑️ Keratinising squamous epithelium erodes ossicles, facial canal and bone.))
- ((Otosclerosis::Stapes fixation — conductive loss without discharge or palsy.))
- ((Mastoiditis::Acute postauricular swelling, not chronic discharge with palsy.))
👩⚕️ Foul discharge + conductive loss + facial palsy = cholesteatoma until proven otherwise.
A patient treated for otitis media now has unsteady gait, dysmetria and fever. Diagnosis?
- ((Cerebellar abscess::☑️ Otitis media + cerebellar signs + pyrexia points to posterior fossa abscess.))
- ((Haematoma::No trauma; doesn't cause fever.))
- ((Subarachnoid haemorrhage::Thunderclap headache, no fever.))
- ((Cerebellar infarction::Causes ataxia but not fever.))
A Chinese patient presents with epistaxis, conductive deafness and a neck mass. Diagnosis?
- ((Maxillary carcinoma::Causes facial pain, cheek numbness, not Eustachian dysfunction.))
- ((Adenoid cystic carcinoma::Salivary gland tumour with perineural spread.))
- ((Pleomorphic adenoma::Benign, painless parotid lump.))
- ((Nasopharyngeal carcinoma::☑️ EBV-associated SCC; blocks Eustachian tube → conductive loss; common in East Asians.))
- ((Ethmoidal polyp::Bilateral, allergic, no neck mass.))
A woodworker with anosmia, nasal pain and retro-orbital pain. Diagnosis?
- ((Ethmoid sinus adenocarcinoma::☑️ Hard wood dust → ethmoid adenocarcinoma; close proximity to orbit causes retro-orbital pain.))
- ((Maxillary sinus carcinoma::Classically in smokers; cheek numbness, oroantral fistula.))
- ((Nasal polyps::Painless obstruction, hyposmia, no pain.))
- ((Maxillary sinusitis::Acute, settles with antibiotics.))
A salivary tumour with prominent perineural invasion on histology. Diagnosis?
- ((Warthin's tumour::Benign cystic; smokers; bilateral in 10%.))
- ((Pleomorphic adenoma::Benign; recurs locally if incompletely excised.))
- ((Adenoid cystic carcinoma::☑️ Hallmark perineural spread; cribriform "Swiss cheese" histology; late recurrence.))
- ((Mucoepidermoid carcinoma::Most common salivary malignancy but rarely perineural.))
- ((Acinic cell carcinoma::Low-grade; not classically perineural.))
A 50-year-old with bilateral parotid swelling, dry mouth and bilateral CN VII palsies that improve with steroids. Diagnosis?
- ((Pleomorphic adenoma::Benign, unilateral, no facial palsy.))
- ((Adenoid cystic carcinoma::Unilateral, painful, perineural.))
- ((Sjögren's syndrome::Causes dry mouth and parotid swelling but no facial palsy.))
- ((Sarcoidosis (Heerfordt syndrome)::☑️ Bilateral parotitis + uveitis + CN VII palsy + fever; steroid-responsive.))
- ((Sialolithiasis::Unilateral postprandial swelling, no palsy.))
Parotid FNA shows lymphocytes only; CT reveals lobulated mass and para-aortic lymphadenopathy. Next step?
- ((Repeat FNAC::Already non-diagnostic; lymphoma needs architecture.))
- ((Superficial parotidectomy::Unnecessary if lymphoma — treated with chemo-radiotherapy.))
- ((Lumpectomy::Inadequate sampling for lymphoma.))
- ((Open biopsy::☑️ Lymphoma requires tissue architecture; treatment is medical, so avoid parotidectomy.))
👩⚕️ Lymphocytic FNA + lymphadenopathy = think lymphoma, not epithelial tumour.
A smoker with hoarseness and a unilateral vocal cord nodule. Most likely diagnosis?
- ((Adenocarcinoma::Rare in larynx; arises in glandular epithelium.))
- ((Adenoid cystic carcinoma::Minor salivary gland tumour, not vocal cord.))
- ((Squamous cell carcinoma::☑️ Most common laryngeal malignancy; strongly linked to smoking and alcohol.))
- ((Melanoma::Mucosal melanoma exists but is rare.))
After submandibular gland excision the tongue deviates toward the side of surgery. Which nerve was injured?
- ((Marginal mandibular::Lower lip droop, not tongue deviation.))
- ((Hypoglossal (CN XII)::☑️ Tongue deviates TOWARDS the side of injury due to unopposed contralateral genioglossus.))
- ((Lingual::Sensory and taste loss to anterior two-thirds of tongue; no motor effect.))
- ((Glossopharyngeal::Posterior third sensation and taste; no tongue motor supply.))
- ((Spinal accessory::Supplies SCM and trapezius.))
A patient with anhidrosis and loss of ciliospinal reflex. Which ganglion is responsible?
- ((Ciliary::Parasympathetic from CN III; pupillary constriction and accommodation.))
- ((Gasserian::Sensory trigeminal ganglion, not autonomic.))
- ((Stellate::☑️ Sympathetic relay for the head/neck; disrupted in Horner's, abolishing the ciliospinal reflex.))
- ((Pterygopalatine::Parasympathetic — lacrimal and nasal glands.))
- ((Submandibular::Parasympathetic — submandibular and sublingual glands.))
Revision summary
- Ear compartments: outer (otitis externa), middle (AOM → bulging TM; mastoiditis; cholesteatoma — foul discharge, conductive loss, CN VII palsy), inner (Meniere's, vestibular schwannoma — unilateral SNHL).
- Weber: conductive → affected ear; sensorineural → unaffected ear. Rinne: AC > BC is normal or sensorineural; BC > AC is conductive.
- Little's area = anterior septum, fed by sphenopalatine (most cauterised), greater palatine, superior labial (ECA branches) and anterior ethmoidal (ICA). Posterior epistaxis = sphenopalatine, harder to control.
- Sinusitis: maxillary most common (ostium against gravity). Posterior ethmoid → superior meatus; rest drain into middle meatus; sphenoid → sphenoethmoidal recess.
- Centor (CENT) ≥3 → treat strep tonsillitis with penicillin V (not amoxicillin → EBV rash).
- Quinsy: uvula deviates AWAY from abscess. Ludwig's angina: bilateral submandibular cellulitis, airway threat.
- Stridor: croup (slow, barking), epiglottitis (toxic, drooling — don't examine), foreign body (sudden).
- Hoarseness: RLN palsy from lung cancer, thyroid surgery, aortic arch aneurysm. Left RLN longer (loops under aorta).
- Salivary 80s: 80% parotid, 80% benign, 80% pleomorphic adenoma. Submandibular = 8% of tumours but 50% malignant — excise.
- Adenoid cystic carcinoma = perineural invasion, facial palsy, late recurrence. Heerfordt = sarcoid (parotid + uveitis + VII + fever). Sjögren's = dry + RA, no palsy.
- Wood dust → ethmoid adenocarcinoma. EBV → nasopharyngeal carcinoma.