Rhinitis and Rhinorrhoea. Flashcards
What is rhinitis?
Acute or chronic inflammation of the nasal mucosa characterized by:
rhinorrhoea (runny nose)
Sneezing
Itching
Nasal congestion and obstruction (swelling of nasal mucosa largely due to dilated blood vessels- particularly in cavernous sinusoids).
How is rhinitis classified?
Allergic
Non-allergic
Mixed
a) What are the types of allergic rhinitis?
b) Which other respiratory disease is allergic rhinitis similar to and strongly linked to?
a) Seasonal
Perennial (year round)
Episodic (sporadic- can’t predict when it will come)
b) allergic asthma.
What are the symptoms of a) the acute stage and b) the delayed phase of allergic rhinitis?
a) Itching, sneezing, rhinorrhoea and nasal congestion
b) Congestion and obstruction
Which inflammatory cells are involved in allergic rhinitis?
Mast cells, basophils and eosinophils.
Which type of Ig is involved in allergic rhinitis?
IgE
What is non-allergic rhinitis?
Any acute or chronic rhinitis that does not involve IgE-dependent events
What are possible causes of non-allergic rhinitis?
Infection- infectious rhinitis (largely viral)
Hormonal imbalance - hormonal rhinitis (e.g. in pregnancy)
vasomotor disturbances- vasomotor rhinitis (idiopathic)
Non-allergic rhinitis with eosinophilia syndrome (NARES)
Medications- drug induced rhinitis
Give an example of a mixed rhinitis
Occupational rhinitis
How do rhinitis and rhinorrhoea cause difficulty breathing in through the nose?
They cause increased blood flow and increased vascular permeability. These increase the volume of the nasal mucosa.
Describe the mechanism of action of glucocorticoids in the treatment of rhinitis
Reduce vascular permeability
reduce recruitment and activity of inflammatory cells
Reduce the release of cytokines and inflammatory mediators
Which types of rhinitis are glucocorticoids used to treat?
SAR
PAR
NARES
Vasomotor rhinitis
How are glucocorticoids delivered in the treatment of rhinitis?
Intranasally, as a spray
Usually once daily
May also be given orally (short term) in severe cases
Name some examples of glucocorticoids used in the treatment of rhinitis
Beclametasone
Fluticasone
Prednisolone (oral)
Describe the mechanism of anti-histamines used to treat rhinitis.
They are competitive antagonists of H1 receptors. They reduce the effects of mast cell derived histamine.
These effects include:
vasodilation and increased capillary permeability
activation of sensory nerves
mucous secretion from submucosal glands
Which types of rhinitis are anti-histamines used to treat?
SAR
PAR
episodic AR
How are anti-histamines administered in the treatment of rhinitis?
Orally
As an intra-nasal spray
Why are second generation antihistamines preferred to first generation antihistamines?
These reduce sedation as they do not cross the blood brain barrier
They also lack anti-cholinergic effects
Name some examples of second generation antihistamines.
Loratidine
Fexofenadine
Cetirizine
Name an antihistamine delivered intra-nasally
azelastine
Describe the mechanism of action of muscarinic receptor antagonists in the treatment of rhinitis.
Ach released from post-ganglionic parasympathetic fibres act on muscarinic receptor on the nasal mucosa, causing a water secretion that contributes to rhinorrhoea.
This is blocked by muscarinic receptor antagonists.
Which types of rhinitis are muscarinic receptor antagonists used to treat?
PAR and SAR
How are muscarinic receptor antagonists delivered in rhinitis?
Via the nasal route
Name the only muscarinic receptor antagonist used to treat rhinitis.
Ipratropium
a) Name a cromolin used to treat rhinitis.
b) What type of rhinitis does it treat?
c) How is it administered?
a) Sodium chromoglicate
b) Allergic
c) Via the nasal route
Describe the mechanism of action of cysLT1 receptor antagonists in the treatment of rhinitis.
Reduce the effects of cysLTs on the nasal mucosa.
cysLT1 receptor antagonists are equi-effective with which other type of drug?
H1 receptor antagonists.
How are cysLT1 receptor antagonists administered in the treatment of rhinitis?
Via the oral route
What group of patients should be considered in particular for treatment with cysLT1 receptor antagonists?
Patients with both allergic rhinitis and asthma.
What is the only cysLT1 receptor antagonist used to treat rhinitis?
Montelukast
Describe the mechanism of action of vasoconstrictors in the treatment of rhinitis.
They act as direct or indirect sympathomimetics to mimic the effects of NA
Produce vasoconstrcition via activation of alpha-1 adrenoceptors to reduce swelling in the vascular mucosa.
a) Name an alpha 1 adrenoceptor agonist used to treat congestion in allergic rhinitis.
b) How is it delivered?
a) oxymetazoline.
b) via the nasal route
Why is nasal administration of oxymetazoline for more than a few days not recommended?
This is due to the development of a rebound increase in nasal congestion upon discontinuation (rhinitis medicamentosa).
This occurs due to receptor desensitization and downregulation.
