Other nasal problems: rhinolith, nasal myiasis, synechiae, antrochoanal polyp and CSF leak
- Topic
A one-sided blocked or smelly nose has a short list of causes: a stone, maggots, scar bands, a single polyp or leaking brain fluid.
See it in 3D: Nasal cavity · Nasal septum · Inferior nasal conchae · Maxillary sinus · Ethmoid bone
What it is
Most nasal blockage is two-sided and inflammatory. When it is one-sided, the list changes: a foreign body or the stone that forms around it (rhinolith), fly larvae in a neglected nose (nasal myiasis), scar bands after surgery or cautery (synechiae), a single polyp growing out of the maxillary sinus (antrochoanal polyp), a tumour, or clear fluid from the skull base (CSF leak). Each has a clue in the history and a typical look on nasal endoscopy. Nasal myiasis matters in rural Colombia: the New World screwworm lays its eggs at the nostril and its larvae eat living tissue, so it is an emergency. The approach to a runny nose and CSF leak is on its own page; here the focus is on recognising these problems and the next step.
Structure
- Rhinolith: a calcified mass built around a nucleus, either exogenous (bead, seed, paper, cotton) or endogenous (blood clot, dried mucus).
- Nasal myiasis: infestation of the nasal cavity by fly larvae; in the Americas mainly Cochliomyia hominivorax, which can bore into the sinuses, orbit and skull base.
- Synechia: a band of scar tissue between the septum and the lateral wall, usually the inferior or middle turbinate.
- Antrochoanal polyp: a benign cystic polyp from the maxillary sinus mucosa that leaves through an ostium and grows backwards to the choana and nasopharynx (antral, nasal and choanal parts).
- CSF rhinorrhoea: a breach of the dura and bone of the skull base (cribriform plate, ethmoid or sphenoid roof); traumatic (including surgical) or spontaneous.
Problems of the nasal cavity at a glance
| Problem | Typical patient | Key clue | Treatment |
|---|---|---|---|
| Rhinolith | Adult or older child | Hard gritty mass, one-sided fetor | Endoscopic removal, sometimes in fragments |
| Nasal myiasis | Neglected, elderly or disabled rural patient; atrophic or ulcerated nose | Live larvae, pain, bloody discharge, swelling | Admission, larvae removal, ivermectin, antibiotics if infected |
| Synechiae | After nasal surgery, cautery or packing | Scar band septum to turbinate | Division and a temporary septal splint |
| Antrochoanal polyp | Teenager or young adult | Single polyp reaching the choana | Endoscopic removal including its sinus part |
| CSF leak | After head injury or skull base surgery, or spontaneous | Clear one-sided drip; beta-2 transferrin positive | Conservative care, then endoscopic repair |
In clinical practice
- Rhinolith: slowly increasing one-sided blockage, foul (fetid) discharge, smell of rot, occasional bleeding; a hard, gritty grey mass on probing.
- Nasal myiasis: intense pain, itching or a crawling feeling, bloody foul discharge, swelling of the nose, face or eyelids, sneezing out larvae or seeing them move; it can destroy the septum, palate and orbit and reach the meninges.
- Synechiae: nasal blockage some weeks after surgery or cautery; seen as a band on rhinoscopy or endoscopy.
- Antrochoanal polyp: one-sided blockage, often worse on breathing out; the smooth grey mass may be seen behind the soft palate.
- A one-sided polyp or mass in an adult is not assumed benign: inverted papilloma and cancer must be excluded.
- CSF leak: clear, salty, one-sided drip that increases when leaning forward or straining; headache; recurrent meningitis is a warning that a leak exists.
Next step / Initial management
- First workup of one-sided blockage or discharge: anterior rhinoscopy after decongestant and, by ENT, nasal endoscopy; sinus CT for rhinolith, polyp or suspected CSF leak.
- Nasal myiasis: refer the same day for admission; ENT removes the larvae (under endoscopy when deep), ivermectin is used as an adjunct, secondary infection is treated, CT shows the extent, and tetanus status is updated; look for the underlying cause and for neglect.
- Rhinolith and suspected foreign body: priority ENT referral for removal under good light and anaesthesia; never push the object backwards.
- Antrochoanal or any one-sided polyp: priority referral (within weeks) for endoscopy, CT and removal with histology.
- Suspected CSF leak: urgent referral to ENT or neurosurgery; collect the fluid for beta-2 transferrin, advise against nose blowing and straining, and teach the signs of meningitis.
- Synechiae causing blockage: routine ENT referral for division.
Test yourself
Think of the answer, then tap the question to see it.
A 78-year-old bedridden man from rural Colombia has severe nasal pain, bloody foul discharge and facial swelling; his carer saw worms in the nose. What is the diagnosis and the next step?
Nasal myiasis, most often by the New World screwworm. Same-day referral for admission, larvae removal, ivermectin as adjunct, antibiotics and CT for extent.
A 16-year-old has one-sided nasal blockage. Endoscopy shows a single smooth grey polyp from the middle meatus reaching the nasopharynx. What is it?
An antrochoanal polyp, arising in the maxillary sinus; it is removed endoscopically together with its sinus part to prevent recurrence.
A woman has had a one-sided foul nasal discharge for years. Probing touches a hard, gritty mass. What is the likely diagnosis?
A rhinolith: calcified material around a foreign body or clot; removed by ENT under endoscopy.
Clear fluid drips from one nostril a week after a head injury. Which test confirms its origin?
Beta-2 transferrin in the fluid, which is specific for CSF; then imaging of the skull base and ENT or neurosurgical care.
Connections
See it in 3D5
The structures of Durgical's 3D anatomy where it is found.
Microorganisms1
In Pharmacology1
Educational content; it does not replace a medical assessment and is not a clinical instruction. For a real case, follow current guidelines and specialist advice.
Sources: Nasal Foreign Body (StatPearls Publishing (NCBI Bookshelf), 2023); Myiasis (DPDx: Laboratory Identification of Parasites of Public Health Concern) (Centers for Disease Control and Prevention (CDC), 2024); About Myiasis (Centers for Disease Control and Prevention (CDC), 2024); Nasal Polyps (StatPearls Publishing (NCBI Bookshelf), 2025); Cerebrospinal Fluid Leak (StatPearls Publishing (NCBI Bookshelf), 2025).
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Representative model, for educational purposes only.