Nose Flashcards
What is the pathophysiology of allergic rhinitis?
IgE mediated type 1 hypersensitivity reaction
Initial inhalation of antigen causes B cells to form antigen-specific IgE.
Allergen is cleared and the residual IgE bind to Fc receptors on mast cells.
On subsequent inhalation of antigen, it binds to IgE coated mast cells which then degranulate releasing vasoactive mediators (e.g. histamine)
Inflammatory mediators cause acute allergic symptoms
Delayed recruitment of immune cells causes nasal congestion
How does allergic rhinitis present?
Rhinorrhoea
Itching
Nasal obstruction
Sneezing
What are the two classifications of allergic rhinitis and how do they differ?
Intermittent:
- symptoms less than 4 days a week or under 4 week duration
Persistent:
- symptoms more than 4 days a week or more than 4 weeks duration
What are the two severities of allergic rhinitis?
Mild (no disruption of daily life)
Moderate-severe (disruption of daily life)
What kind of antigens tend to cause intermittent allergic rhinitis?
Antigens present at a certain time of year
often summer, e.g. grass pollen - hayfever
What kind of antigens tend to cause persistent allergic rhinitis?
Antigens present all year round (e.g. dog, cat, dust mite antigens)
What tests can be done to identify the causative antigen in allergic rhinitis?
Skin prick test (prick small amount of various common antigens into skin and observe for allergic response)
RAST blood test (blood test for specific IgE associated with common antigens)
What is the treatment of allergic rhinitis?
Stepwise treatment
- antigen avoidance
- antihistamines (cetirizine)
- topical steroids (beclomethasone)
- antihistamines and steroids
- immunotherapy (in selected patients with severe disease)
Other treatments include leukotriene blockers (montelukast) or decongestants (pseudoephedrine)
What is non-allergic rhinitis?
Inflammation of nasal mucosa with no apparent cause
How does non-allergic rhinitis present?
Congested nose
Rhinorrhoea
Congestion
(no itch, differentiates from allergic rhinitis)
What is a nasal complication of non-allergic rhinitis?
Nasal polyps
What are nasal polyps?
Soft, non-cancerous growths of nasal lining
What causes nasal polyps?
Chronic inflammation of nasal mucosa
- non-allergic rhinitis
- asthma
- aspirin sensitivity
- cystic fibrosis
How do nasal polyps present?
In older people
Anosmia
Rhinorrhoea
Nasal congestion
What condition do you suspect if a young patient presents with nasal polyps?
Cystic fibrosis
How do you treat non-allergic rhinitis?
Steroids
Anti-cholinergic (ipratropium)
How do you treat nasal polyps?
Steroid spray
Surgery (if steroids don’t shrink)
What are the names and locations of the paranasal sinuses?
2 frontal sinuses located behind brow ridges
(formed from one frontal bone and separated by bony septum)
Ethmoidal sinuses situated between upper nasal cavity and orbits
(complex shape of ethmoid divides them into anterior, middle and posterior air cells)
2 sphenoidal sinuses located posterior to nasal cavity
(two sphenoidal sinuses formed from one sphenoid bone)
2 maxillary sinuses/antra located in maxillary bones
(two maxillary sinuses, one in each maxillary bone)
Which meatus does the frontal sinus drain into?
Middle meatus
Which meatus does the ethmoidal sinus drain into?
Superior and middle meatuses
Which meatus does the sphenoidal sinus drain into?
Sphenoethmoidal recess
Which meatus does the maxillary sinus drain into?
Middle meatus
Where is the inferior meatus and what drains into it?
Inferior to inferior concha
Lacrimal fluid
Where is the middle meatus and what drains into it?
Inferior to middle concha
Frontal sinuses, ethmoidal air cells and maxillary sinuses
