Rhinology
The paranasal sinuses look like a set of unrelated air spaces with confusing drainage pathways. They are better understood as a single system with one bottleneck.
Almost all sinus disease is a drainage problem. Mucosa secretes, cilia move the mucus toward an ostium, and the mucus leaves. Block an ostium, and stasis, hypoxia and infection follow in that order.
The bottleneck is the osteomeatal complex, a small region in the middle meatus through which the maxillary, anterior ethmoid and frontal sinuses all drain. Disease anywhere in that narrow area produces disease in three sinuses at once, which is why endoscopic surgery targets the complex rather than the sinuses themselves.
Two further rules generate most of the remaining marks.
Bilateral nasal polyps are inflammatory; a unilateral polyp is a tumour until proved otherwise.
Pain and numbness out of proportion to the appearance in a diabetic means invasive fungal disease, and in India that consideration is not academic.
1. Anatomy That Actually Matters
Drainage determines everything, so it is worth learning as a list rather than a diagram.
| Sinus or duct | Drains into |
|---|---|
| Maxillary, anterior ethmoid, frontal | Middle meatus, via the osteomeatal complex |
| Posterior ethmoid | Superior meatus |
| Sphenoid | Sphenoethmoidal recess |
| Nasolacrimal duct | Inferior meatus |
Two consequences follow directly.
The maxillary ostium sits high on the medial wall, so the sinus must clear mucus against gravity by ciliary action alone. This is why maxillary sinusitis is common, why ciliary dysfunction matters, and why a dependent antrostomy does not work as well as intuition suggests.
The nasolacrimal duct is the only structure draining into the inferior meatus, which is why an inferior meatal antrostomy risks it and why watering of the eye can follow nasal surgery.
Mucociliary clearance
Cilia beat at around 1,000 strokes per minute within a layer of watery periciliary fluid, propelling an overlying mucus blanket toward the ostium.
Anything that thickens the mucus, dries the surface or paralyses the cilia converts a self-cleaning system into a stagnant one. Dehydration, smoking, topical decongestant overuse and cystic fibrosis all act here, as does primary ciliary dyskinesia, which produces the triad of bronchiectasis, sinusitis and situs inversus in Kartagener syndrome.
2. Rhinitis
Allergic rhinitis is an IgE-mediated type I hypersensitivity, and the ARIA classification describes it by duration and severity rather than by season, which suits Indian patients exposed to perennial allergens.
Intranasal corticosteroid is the single most effective drug class, outperforming oral antihistamines for nasal obstruction in particular. Antihistamines are better for sneezing, itching and rhinorrhoea and do little for blockage.
Rhinitis medicamentosa is the trap. Topical decongestants such as xylometazoline produce rebound vasodilatation after a few days, so the patient uses more, obstructs more and becomes dependent. The treatment is withdrawal of the drug under cover of an intranasal steroid, and the practical rule is a maximum of about five days of topical decongestant.
Atrophic rhinitis, with wide crusted nasal cavities, foul odour and paradoxically a sensation of blockage despite a roomy nose, remains more common in parts of India than in Western series. The paradox is explained by loss of the sensory feedback that normally signals airflow.
3. Nasal Polyps
Polyps are oedematous, prolapsed mucosa, insensitive to touch and pale rather than pink, which distinguishes them from a hypertrophied turbinate.
Bilateral polyps are inflammatory and belong to chronic rhinosinusitis with nasal polyposis, often with type 2 inflammation.
A unilateral polyp in an adult is a neoplasm until imaging and histology say otherwise. Inverted papilloma is the classic possibility, carrying a risk of malignant transformation and a strong tendency to recur if incompletely excised.
A unilateral polypoid mass in a child may be an encephalocele or meningocele, and biopsying it produces a cerebrospinal fluid leak and meningitis. Imaging comes before instruments.
Two associations are worth carrying. Samter triad is nasal polyposis, asthma and aspirin sensitivity. Polyps in a child raise the question of cystic fibrosis, which should be actively considered rather than assumed absent.
4. Rhinosinusitis
Acute
Most acute rhinosinusitis is viral and resolves. The features suggesting bacterial infection are symptoms persisting beyond about ten days without improvement, unusually severe symptoms with fever and purulent discharge, or double worsening, in which the patient improves and then deteriorates.
That last pattern is the most specific and the most often ignored.
Chronic
Chronic rhinosinusitis is defined by twelve weeks or more of symptoms with objective evidence on endoscopy or CT. EPOS 2020 divides it into disease with and without nasal polyps, and increasingly by endotype, particularly whether type 2 inflammation is present.
Medical treatment is intranasal corticosteroid and saline irrigation, with surgery reserved for failure. Endoscopic sinus surgery aims to restore drainage through the osteomeatal complex rather than to strip the sinuses.
Biologics have changed the refractory end of this disease. Dupilumab, targeting interleukin-4 and interleukin-13 signalling, was the first approved for polyposis, followed by omalizumab and mepolizumab. Current guidance restricts them to patients with evidence of type 2 inflammation who remain uncontrolled after standard treatment, and the practical trend has been toward starting them earlier.
5. Complications of Sinusitis
The sinuses are separated from the orbit by paper-thin bone and from the brain by little more, so infection spreads by continuity and through valveless veins.
Orbital complications are graded by the Chandler classification.
| Stage | Lesion |
|---|---|
| I | Preseptal cellulitis |
| II | Orbital cellulitis |
| III | Subperiosteal abscess |
| IV | Orbital abscess |
| V | Cavernous sinus thrombosis |
The clinical divide is at the orbital septum. Preseptal disease has normal vision, normal eye movements and no proptosis. Postseptal disease has proptosis, restricted or painful eye movement, and threatened vision.
Loss of colour vision or a relative afferent pupillary defect indicates optic nerve compromise and demands urgent decompression.
Intracranial complications include meningitis, subdural empyema, brain abscess and cavernous sinus thrombosis. Pott puffy tumour is a subperiosteal abscess of the frontal bone with underlying osteomyelitis, presenting as a boggy forehead swelling, and it implies intracranial extension until excluded.
6. Fungal Sinusitis
Fungal disease divides by whether it invades tissue, and the division decides urgency.
Non-invasive forms are the fungal ball, typically in a single maxillary sinus in an immunocompetent adult, and allergic fungal rhinosinusitis, which produces eosinophilic mucin, expansion of the sinuses and a characteristic heterogeneous appearance on imaging.
Acute invasive fungal rhinosinusitis is a surgical and medical emergency, and rhino-orbital-cerebral mucormycosis is its most feared form.
India carried roughly 81 per cent of the world's COVID-associated cases during the 2021 wave, and the drivers were the ones that matter generally: uncontrolled diabetes with ketoacidosis, corticosteroid exposure, and iron availability.
Recognising it early
The early signs are deceptive because the nasal cavity can look unimpressive.
Facial or dental pain and numbness out of proportion to the findings, unilateral facial swelling, a black eschar on the palate or turbinate, and progressive ophthalmoplegia are the features to act on. Numbness matters because the fungus is angioinvasive and infarcts nerves, and an insensate area of mucosa is dead tissue.
Treatment is combined: urgent surgical debridement of all necrotic tissue, systemic liposomal amphotericin B, and aggressive correction of the underlying metabolic state.
The evidence for combining the two is stark. Reported survival in large series was around 3 per cent with no intervention, roughly 57 per cent with surgery alone, about 61 per cent with amphotericin alone, and around 70 per cent with both. Neither modality substitutes for the other.
7. Adenoids and the Sense of Smell
Adenoid hypertrophy
The adenoid is nasopharyngeal lymphoid tissue that enlarges through early childhood and involutes from about age seven, which is why its diseases are diseases of small children.
Obstruction produces mouth breathing, snoring, hyponasal speech and obstructive sleep apnoea. Persistent mouth breathing over years gives the adenoid facies: an open mouth, a high arched palate, shortened upper lip and a retrognathic appearance.
Blockage of the Eustachian tube orifice produces otitis media with effusion, which is why adenoidectomy is an effective adjunct when grommets are inserted.
The examinable link is that adenoidal enlargement explains three apparently separate complaints at once, nasal, aural and sleep-related, so a child with any one of them should be asked about the other two.
Disorders of smell
Smell is lost in three broad ways, and the mechanism decides the prognosis.
Conductive loss occurs when odorants cannot reach the olfactory cleft, as in polyposis, severe rhinitis or a deviated septum. It is potentially fully reversible once airflow is restored.
Sensorineural loss follows damage to the olfactory epithelium or nerve, classically after a viral infection, and recovers slowly and often incompletely. Post-viral anosmia became far more visible after COVID-19, and olfactory training, repeated deliberate sniffing of a fixed set of odours, has the best evidence for improving recovery.
Central loss follows head injury, with shearing of olfactory filaments at the cribriform plate, or neurodegenerative disease. Anosmia can precede the motor features of Parkinson disease by years.
Two clinical points follow. Unilateral anosmia is never normal and warrants examination and imaging, unlike bilateral loss with an obvious nasal cause. And loss of smell removes most of what patients call taste, since flavour is largely retronasal olfaction, so a patient complaining of lost taste with normal tongue sensation usually has an olfactory problem.
8. The Deviated Septum and Nasal Obstruction
A deviated nasal septum is extremely common and mostly asymptomatic, so the finding alone does not explain a blocked nose.
Three points separate the deviation that matters from the one that does not.
Obstruction is usually worst opposite the deviation, because the wider side develops compensatory inferior turbinate hypertrophy, so patients frequently point to the wrong nostril.
The nasal cycle alternates congestion between the two sides every few hours in normal people, which is why a patient can report the blockage switching sides and why examination at a single moment can mislead.
Septoplasty corrects the septum, not the turbinates, so a deviation with significant contralateral turbinate hypertrophy usually needs both addressed.
A septal haematoma after trauma is the urgent exception. It strips the perichondrium from cartilage which depends on it for nutrition, so untreated it produces cartilage necrosis, a septal perforation and a saddle nose deformity within days. It must be drained.
9. Epistaxis and CSF Rhinorrhoea
Ninety per cent of nosebleeds are anterior, from Little's area on the septum where the Kiesselbach plexus is formed by branches of the sphenopalatine, greater palatine, anterior ethmoidal and superior labial arteries.
Posterior bleeding, usually from the sphenopalatine artery, is commoner in older hypertensive patients, is harder to control, and can present as bleeding down the throat with an apparently dry nose.
Management escalates from first aid and cautery, through anterior and then posterior packing, to sphenopalatine artery ligation or embolisation.
Clear unilateral watery rhinorrhoea after head injury or sinus surgery may be cerebrospinal fluid. The confirmatory test is beta-2 transferrin, which is present in cerebrospinal fluid and not in nasal secretions. The old glucose test is unreliable and the halo sign is suggestive at best.
Managing the acute bleed
Two practical points decide outcomes more than any choice of packing material.
Resuscitate before you look. A patient bleeding briskly from the nose can lose a substantial volume unnoticed because much of it is swallowed, so pulse, blood pressure and pallor are assessed before the endoscope is picked up.
Anticoagulation and hypertension are treated alongside the nose, not afterwards, since neither cautery nor packing will hold against an uncorrected cause.
10. Worked Examples
Example 1. A 58-year-old man with poorly controlled diabetes has three days of left facial pain and numbness of the cheek. The nasal cavity looks almost normal apart from a dusky area on the middle turbinate. What must be excluded and how?
Acute invasive fungal rhinosinusitis, most likely mucormycosis. The combination of an unimpressive nasal appearance with pain and numbness out of proportion is characteristic, and numbness specifically indicates angioinvasion with nerve infarction, so a dusky or insensate turbinate is dead tissue rather than inflammation.
He needs urgent nasal endoscopy with biopsy for KOH mount and histopathology showing broad aseptate hyphae with right-angle branching, contrast imaging of sinuses, orbit and brain, and immediate correction of his glycaemia and any acidosis. Treatment is combined surgical debridement and systemic liposomal amphotericin B, since survival with either alone is substantially worse than with both.
Example 2. A 45-year-old woman has a single polypoid mass in the right nasal cavity with unilateral obstruction and occasional bleeding. A colleague plans to remove it in clinic. Comment.
This should not be removed in clinic. Bilateral polyps are inflammatory, but a unilateral polyp in an adult is a neoplasm until proved otherwise, and inverted papilloma is the leading possibility, with a risk of harbouring or developing squamous carcinoma and a strong tendency to recur if incompletely excised. Occasional bleeding raises that suspicion further, since inflammatory polyps rarely bleed.
The correct sequence is cross-sectional imaging first, followed by biopsy or excision in a controlled setting, with a surgical plan that achieves complete removal including the attachment.
Example 3. A 7-year-old with sinusitis develops swelling of the left eyelid. The eye moves fully, vision is normal and there is no proptosis. Two days later he has proptosis and painful restricted eye movement. What has changed, and what is now required?
He has progressed from preseptal cellulitis, Chandler stage I, to postseptal orbital involvement, at least stage II. The orbital septum is the anatomical divide: preseptal disease spares vision, eye movement and globe position, while postseptal disease produces proptosis, restricted or painful movement and threatens sight.
He now needs urgent contrast CT of the sinuses and orbits to look for a subperiosteal abscess, intravenous antibiotics, and joint ENT and ophthalmology assessment with formal visual acuity and colour vision testing. Loss of colour vision or a relative afferent pupillary defect indicates optic nerve compromise and mandates urgent surgical decompression.
Example 4. A patient uses xylometazoline drops several times daily for three months and complains that his nose is more blocked than ever. Explain and treat.
Rhinitis medicamentosa. Topical alpha-agonist decongestants produce vasoconstriction initially, but after a few days the vessels rebound with vasodilatation as the drug wears off, so obstruction returns worse than baseline. The patient increases the dose, which shortens the interval further, producing a self-reinforcing cycle and tachyphylaxis.
Treatment is withdrawal of the decongestant, which will worsen symptoms transiently, under cover of an intranasal corticosteroid, and explicit counselling that the initial deterioration is expected and temporary. The general rule is that topical decongestants should not be used for more than about five days.
Example 5. A patient develops clear watery discharge from one nostril after endoscopic sinus surgery, worse on leaning forward. Which test settles the question?
Beta-2 transferrin. It is a variant of transferrin produced by neuraminidase activity in the central nervous system and is present in cerebrospinal fluid, perilymph and aqueous humour but not in nasal secretions, tears or serum, so its presence in the fluid confirms a cerebrospinal fluid leak.
The traditional glucose test is unreliable because nasal secretions can contain glucose and blood contamination confounds it, and the halo or double ring sign on filter paper is suggestive rather than diagnostic. Confirmation matters because a leak means a breach of the skull base with a continuing risk of meningitis, and it requires imaging to locate the defect and definitive repair.
Summary
Sinus disease is a drainage problem, and the osteomeatal complex is the bottleneck.
Maxillary, anterior ethmoid and frontal sinuses all drain into the middle meatus.
The nasolacrimal duct is the only structure draining into the inferior meatus.
The maxillary ostium sits high, so clearance works against gravity by cilia alone.
Intranasal corticosteroid outperforms antihistamines for nasal obstruction.
Topical decongestants beyond about five days cause rhinitis medicamentosa.
Bilateral polyps are inflammatory; a unilateral adult polyp is a tumour until proved otherwise.
A unilateral polypoid mass in a child may be an encephalocele: image before biopsy.
Samter triad is polyps, asthma and aspirin sensitivity; polyps in a child raise cystic fibrosis.
Double worsening is the most specific sign of bacterial rhinosinusitis.
Chronic rhinosinusitis needs twelve weeks of symptoms plus objective evidence.
EPOS 2020 divides chronic disease by polyps and by endotype, particularly type 2 inflammation.
Dupilumab, omalizumab and mepolizumab are reserved for uncontrolled type 2 disease.
Chandler grades orbital complications from preseptal cellulitis to cavernous sinus thrombosis.
The orbital septum is the divide: proptosis and restricted movement mean postseptal disease.
Pott puffy tumour is frontal osteomyelitis with a subperiosteal abscess and implies intracranial risk.
Invasive fungal sinusitis presents with pain and numbness out of proportion to the appearance.
India carried around 81 per cent of COVID-associated mucormycosis cases in 2021.
Survival needs both surgery and amphotericin, at roughly 70 per cent, against about 57 to 61 per cent with either alone.
Ninety per cent of epistaxis is anterior from Little's area; posterior bleeds come from the sphenopalatine artery.
Beta-2 transferrin confirms cerebrospinal fluid rhinorrhoea; glucose testing does not.
