Rhinitis and Rhinorrhoea Flashcards
What is rhinitis
Rhintiis is a common disease causing acute and chronic inflammation of nasal mucosa
Symptoms of rhinitis
Rhinorrhoea - Runny nose, watery mucous accumulation in nasal cavity
Sneezing, itching, nasal congestion and obstruction
What causes nasal congestion and obstruction
Swelling of nasal mucosa largely due to dilated blood vessels
Types of rhinitis
Allergic, non-allergic and mixed
What is rhinitis also known as
Coryza
Types of allergic rhinitis
Seasonal, perennial and episodic
Pathology of allergic rhinitis
Inhalation of allergen increases specific levels of IgE. This IgE binds to mast cells and basophils. Re-exposure to allergen causes mast cell and basophil degranulation. This causes release of mediators including histamine, cysLT, tryptase,prostaglandins causing acute sneezing, itching, rhinorrhea and nasal congestion
What is non-allergic rhinitis
Any rhinitis that doesn’t involve IgE dependant events
Causes of non-allergic rhinitis
Infectious, hormonal, vasomotor disturbance or idiopathic, drug induced, nonallergic rhinitis with eosinophillic syndrome (NARES)
Occupational rhintis
Rhinitis may involve allergic and non-allergic rhinitis
Target of rhinitis and rhiorrhoea
Anti-inflammatory (glucocorticoids), mediator receptor blockade (H1 receptor antagonist/CysLT1 receptor antagonist), nasal blood flow (vasoconstriction) and anti-allergic (sodium cromoglicate)
Mainstay therapy of seasonal and perineal allergic rhinitis
Glucocorticoids
What are NARES
Nonallergic rhinitis with eosinophilic syndrome
Mechanism of glucocorticoids in rhinitis
Reduce vascular permeability, recruitment and activity of inflammatory cells and release of cytokines and mediators
What drugs are effective in seasonal, perinneal and episodic rhinitis but less in non-allergic
H1 receptor antagonist (H1 receptor)
Ex: Cetrizine, loratidine, fexofenadine
What symptoms do glucocorticoids reduce in rhinitis
All over several weeks
What symptoms do anti-histamine relieve
Less effect upon congestion than other symptoms
Mechanism of muscarinic receptor antagonist
ACh release from post-ganglionic parasympathetic fibres activates muscarinic receptors on nasal glands causing watery secretion that contributes to rhinorrhea. Ex: Ipratropium
What symptoms do muscarinic receptor antagonists relieve
Rhinorrhoea in seasonal and perinneal allergic rhinitis but none other
Mechanism of sodium cromoglicate in rhinitis
Mast cell stabilization
What is sodium cromoglicate used for
Maintenance treatment of allergic rhinitis
Mechanism of Cysteinyl Leukotriene receptor antagonist
Reduce effect of CysLT on nasal mucosa
Drug choice for patients with allergic rhinitis and asthma
CysLT’s receptor antagonist ex: Montelukast
Effectiveness of treating H1 receptor vs CysLT 1 receptor antagonist in seasonal and perennial alllergic rhinitis
Both have the same efficacy with which their effect maybe additive
Mechanism of vasoconstrictors
Act directly or indirectly to mimic effect of adrenaline. Produce vasoconstriction via activation of alpha1-adrenoceptors in vascular mucosa. Ex: Oxymetazoline
Why shouldn’t Oxymetazoline be used for more than a few days
Rhinitis medicamentosa - Condition of rebound nasal congestion bought on by extended use of topical decongestants. This can lead to increase nasal congestion upon discontinuation
