(PM3A) ENT - Nose Flashcards
Where are hairs in the nose that help to filter particles?
Nasal vestibule
What are the 3 bones in the nasal cavity?
Turbinates
(1) Superior turbinates
(2) Middle turbinates
(3) Inferior turbinates
What are the components of the nasal-associated lymphoid tissue?
(1) Tonsils
(2) Nasopharynx
Where is the respiratory mucosa?
On the turbinates (3 bones) in the nasal cavity
What sinuses are there in the nose?
(1) Frontal sinus (two of these)
(2) Sphenoid sinus
What is the cribriform plate?
Between the olfactory mucosa + olfactory bulb in brain
Bone-like structure
What are some of the key roles of the nose?
(1) Breathing
(2) Air-conditioning
(3) Filtration + purification
(4) Sinus ventilation
(5) Nasal resistance
(6) Vocal resonance
(7) Olfaction - smell
What is the role of the nose in breathing?
Nose is primary way to breathe
What is the role of the nose in air-conditioning?
Nasal mucosa adjusts temperature + humidity
Before entering lungs
What is the role of the nose in filtration and purification?
Hairs filter + trap
Mucous captures smaller particles
Swallow particles in nasopharynx
Secretions (IgA) to kill microorganisms
What is the role of the nose in sinus ventilation?
Sinuses make mucous to moisturise the nose
What is the role of the nose in nasal resistance?
Maintain positive pressure for respiratory system
What is the role of the nose in vocal resonance?
Chamber helps to produce different sounds
m, n, ng
What is the role of the nose in olfaction?
Olfactory neuroepithelium
Olfactory nerves and bulbs control olfaction (smell)
What is olfaction?
Smell
How does smell work? What is the mechanism?
(1) Detection of odour by olfactory receptor neurons in the olfactory epithelium
(2) Transmits signal through cribriform plate to mitral cells in the olfactory bulb in the brain
(3) Olfactory receptor neurons are supported by sustentacular cells (SuC) in olfactory epithelium
(4) Stem cells in olfactory epithelium can replace sustentacular cells and olfactory receptor neuron cells
How can sense of smell be affected?
Damaged/ loss of:
(1) Olfactory receptor neurons
(2) Sustentacular cells
(3) Mitral cells
Which cells in the nasal cavity are affected by SARS-CoV-2?
Sustentacular cells
What is anosmia?
Lack of smell
What is a sustentacular cell?
Supportive cells in the olfactory epithelium
Support olfactory receptor neurons
What are some of the drug targets delivered through the nose?
(1) Innervation from PNS
(2) Adrenergic receptors - dilation of nose vessels
(3) mAchRs - secretions
(4) Glucocorticoid receptors - inflammation
(5) Histamine H1 receptors/ mast cells - allergy
What are some of the key drugs classes to act on the nose?
(1) Decongestants - sympathomimetic amines
(2) Decongestants - sodium chloride solution 0.9%
(3) Anti-inflammatory glucocorticoid - beclometasone
(4) Suppressors of inflammatory mediator release
(5) Anti-histamines
(6) Anti-cholinergic (parasympatholytic)
What are some of the conditions that affect the nose?
(1) Rhinitis - allergic/ non-allergic
(2) Polyps
(3) Bacterial sinusitis
(4) Nasal staphylococci
(5) Nasal congestion
(6) Rhinorrhea
What is nasal congestion?
Blockage of the nasal cavity
Can be caused by:
- Rhinitis
- Polyps
- Infections (cold/ flu etc)
- Sinusitis
What is rhinorrhea?
Runny nose - excessive production of watery nasal mucous secretions by nasal mucosa
Can be caused by:
- Infections (cold/ flu etc)
- Cold temperature
- Rhinitis
What is allergic rhinitis?
Acute/ chronic inflammation of the nasal mucosa
Caused by allergens
How is inflammation caused in allergic rhinitis?
(1) IgE binds to allergens in the nasal cavity
(2) Leads to release of inflammatory mediators (histamine) from mast cells
What is non-allergic rhinitis?
Acute/ chronic inflammation of the nasal mucosa
NOT caused by allergens
Vasomotor rhinitis
What is vasomotor rhinitis?
Acute/ chronic inflammation of the nasal mucosa
NOT caused by allergens
Non-allergic rhinitis
What is infectious rhinitis?
Acute/ chronic inflammation of the nasal mucosa
Caused by infection
What are some of the symptoms of rhinitis and rhinorrhea?
(1) Blocked nose
(2) Runny nose
(3) Post-nasal drip
(4) Sneezing
What is the treatment for allergic rhinitis?
(1) Removal of allergen
(2) Oral anti-histamine
(3) Nasal decongestants
(4) Intranasal anti-inflammatory corticosteroid
What is the treatment for non-allergic rhinitis?
Congestion - treated with sympathomimetic decongestants (ephedrine/ pseudoephedrine)
Rhinorrhea - iprattropium bromide spray (topical)
What are the common anti-histamines used for treatment of allergic rhinitis?
(1) Cetirizine
(2) Loratidine
(3) Fexofenadine
(4) Acrivastine
(5) INTRANASAL - azelastine
What are common treatments for nasal blockage/ polyps?
(1) INTRANASAL - anti-inflammatory corticosteroid
- e.g. beclometasone/ fluticasone/ mometasone
What are the common treatments for sneezing/ nasal discharge?
(1) ORAL - anti-histamine
(2) INTRANASAL - corticosteroid
- e.g. fluticasone/ mometasone/ beclometasone
How long is the onset of action of intranasal anti-histamines?
Within 15 minutes
How long is the onset of action of oral non-sedating anti-histamines?
Within 1 hour
How long is the onset of action of intranasal corticosteroids?
Within 12 hours
What is the dosing frequency of intranasal anti-histamines?
BD-QDS
What is the dosing frequency of oral non-sedating anti-histamines?
OD
What is the dosing frequency of intranasal corticosteroids?
OD
What drugs target nasal blood flow?
Sympathomimetic agents
(1) Ephedrine
(2) Pseudoephedrine
(3) Xylometazoline
What drugs target anti-inflammatory mediators?
Corticosteroids
(1) Becometasone
(2) Fluticasone
(3) Mometasone
What drugs target suppression of mediator release?
Cromolyn sodium
Omalizumab
What drugs target the mediator receptor blockade?
(1) H1 Receptor antagonists
- e.g. azelastine
(2) Leukotriene antagonists
- e.g. montelukast
What is the mechanism of action for the targeting of nasal blood flow by sympathomimetic agents?
Vasoconstriction
Limitation of histamine effects
What is the mechanism of action for the targeting of anti-inflammatory processes by corticosteroids?
Suppression of inflammation as corticosteroids are anti-inflammatory steroids
What is the mechanism of action for the targeting of suppression of mediator release by cromolyn sodium and omalizumab?
Inhibit histamine release
Monoclonal antibody (mAB) prevents IgE interaction
What is the mechanism of action for the targeting of the mediator receptor blockade by H1 receptor antagonists?
Blocks vasodilation
What is the mechanism of action for the targeting of the mediator receptor blockade by leukotriene antagonists?
Block inflammation
Give some examples of sympathomimetics.
(1) Ephedrine
(2) Pseudoephedrine
(3) Xylometazoline hydrochloride
What is the indirect mechanism of action of sympathomimetics?
(1) Sympathomimetic taken up via noradrenaline transporter in the neurone
(2) Taken into vesicles via vesicular monoamine transporter in exchange for noradrenaline
(3) Released noradrenaline acts on downstream cells by binding to adrenergic receptors
What is the direct mechanism of action of sympathomimetics?
Sympathomimetics act directly on adrenergic receptors
What are nasal polyps?
Non-cancerous growth
Soft growths
Inside the nose sinuses
What is the cause of nasal polyps?
Linked with chronic inflammation
e.g. asthma, infections, etc
What are some of the symptoms of nasal polyps?
(1) Nasal congestion
(2) Rhinorrhea
(3) Nasal drip
(4) Loss of smell/ taste
(5) Nosebleeds
(6) Snoring
What is the treatment for nasal polyps?
(1) Corticosteroid nasal drops/ spray
- to reduce size
(2) Sodium chloride wash
(3) Oral steroids - short-term only
(4) Surgical removal to relieve symptoms
What is sinusitis?
Inflammation of the nasal sinuses
What are the causes of sinusitis?
Usually viral - e.g. rhinovirus
Is sinusitis self-limiting?
Yes
2-3 weeks
What are some of the symptoms of sinusitis?
(1) Blocked nose
(2) Impaired smell
(3) Sinus headache
(4) Green/ yellow mucous
(5) Runny nose
(6) High temperature (>38ºC)
(7) Facial pain
(8) Bad breath
(9) Toothache
What is the treatment for sinusitis?
(1) Self-care - pain management
Only if symptoms have lasted for less than 10 days
What is the treatment for sinusitis if the patient is systemically unwell?
(1) Immediate ABx
- phenoxymethylpenicillin 500mg QDS 5 days
(2) Referral to hospital
What is the first line treatment for severe cases of sinusitis?
(1) Co-amoxiclav 500/125mg TDS 5 days
What is the treatment for sinusitis in patients with symptoms for more than 10 days?
High dose intranasal corticosteroid
No ABx
Consider back-up prescription
What is nasal staphylococci?
Carriage fo staphylococci in the nose
May require admission to hospital
What is the treatment for nasal staphylococci?
(1) Chlorhexidine (broad-spectrum anti-septic) + neomycin (aminoglycoside ABx) cream QDS for 10 days
(2) Mupirocin
- Inhibits bacterial protein and RNA synthesis
- Nasal ointment to eradicate nasal carriage of MRSA
- 2% ointment BD-TDS for 5 days
