L5 Rhinitis

Question 1

What is rhinitis?

Answer 1

Inflammation of nasal lining.

Question 2

What are the 2 major causes of rhinitis?

Answer 2

Viral infection and allergy.

Question 3

What are the 2 classes of allergic rhinitis?

Answer 3

Intermittent (less than 4 days per week, or less than 4 weeks per year).
Persistent (more than 4 days per week or more than 4 weeks per year).

Question 4

What are the 4 phases of allergic rhinitis?

Answer 4

1. sensitisation
2. early phase
3. cellular recruitment phase
4. late phase

Question 5

What occurs in the sensitisation phase of allergic rhinitis?

Answer 5

1. exposure to allergens
2. Production of IgE
3. Mast cells are primed with IgE

Question 6

What occurs in the early phase of allergic rhinitis?

Answer 6

1. mast cells degranulate and release histamine, kinins and prostaglandins
2. local pain, itching (sneezing), vasodilation (rhinorrhea)

Question 7

What occurs in the cellular recruitment phase of allergic rhinitis?

Answer 7

1. local pain, itching and sneezing, vasodilation and rhinorrhea
2. granulocytes and mast cells infiltrate the mucosa

Question 8

What occurs in the late phase of allergic rhinitis?

Answer 8

1. chronic inflammatory response

2. hypersecretion, mucosal hypertrophy and congestion

Question 9

What is the difference between intermittent and persistent allergens? give examples.

Answer 9

Intermittent allergens are seasonal. Eg tree pollen (spring) and grass and weeds (summer).
Persistent allergens are perennial and occur all year round. Eg house dust mites, animal dander and fungal spores.

Question 10

What are the common symptoms of allergic rhinitis?

Answer 10

Nasal itch
sneezing
rhinorrhea
nasal congestion

Allergic conjunctivitis occurs occasionally.

Question 11

What signs and symptoms would lead to a differential diagnosis of intermittent allergic rhinitis?

Answer 11

Predominantly rhinorrhea and sneezing. Symptoms present less than 4 days per week or less than 4 weeks per year.

Question 12

What signs and symptoms would lead to a differential diagnosis of persistent allergic rhinitis?

Answer 12

More congestion and less sneezing/itching.
Chronic sinusitis
Hyposmia.
Symptoms persist more than 4 days per week and more than 4 weeks per year.

Question 13

How would you differentiate between mild and moderate/severe allergic rhinitis?

Answer 13

Mild allergic rhinitis causes no sleep disturbance or impaired daily activities.
Moderate/severe allergic rhinitis causes sleep disturbances, impairment of daily activities and impairment of work/school work.

Question 14

Other than allergy, what are some other causes of rhinitis? What are their signs and symptoms?

Answer 14

Common cold: Purulent discharge, less sneezing and itching, cough, sore throat etc.

Vasomotor rhinitis: less sneezing and itching, caused by environmental factors such as cold air.

Hormonal: pregnancy.

Rhinitis medicamentosa: over-use of topical decongestants (hence 4-5 day limit).

Drug induced: antihypertensives, aspirin and NSAIDs, oestrogens, cocaine

Nasal blockage: deviated septum, history of nose trauma, gets progressively worse (polyps)

Foreign bodies: children 1-3 yrs, unilateral discharge, offensive smelling discharge

Question 15

When should you refer a patient suffering rhinitis to a doctor?

Answer 15

Presence of severe symptoms, either systemic or enough to interfere with daily activities.

Long term symptoms, either intermittent for more than 2 months (seasonal allergy), or more than 4 days per week for more than 3 months (persistent).

Failed medication: chronic overuse of topical decongestants.

Possible blockage, or unilateral discharge in toddlers.

Question 16

What are the pharmacological treatments for rhinitis?

Answer 16

topical decongestants
antihistamines (oral or ocular)
corticosteroids
anticholinergics
mast cell stabilisers

Question 17

What is the mechanism of action of topical decongestants?

Answer 17

alpha-sympathomimetics:

• constrict arterioles to reduce secretion
• fast acting (5-10 mins)
• 6-12h duration

Question 18

What are 3 examples of active ingredients in nasal drops or nasal spray?

Answer 18

oxymetazoline
xylometazoline
tramazoline

Question 19

What is the mechanism of action of antihistamines?

Answer 19

H1-receptor specific: block action of histamine at these receptors to reduce odema and secretions.

Question 20

Compare the efficacy of 1st, 2nd and 3rd gen antihistamines.

Answer 20

All have similar efficacy in rhinitis.
2nd and 3rd gen do not penetrate CNS as much as the 1st gen, so less drowsiness.
1st gen have significant anti cholinergic activity.

Question 21

Give an example of a long-acting 1st gen oral antihistamine?

Answer 21

Promethazine

Question 22

Give an example of a 1st gen moderate-duration oral antihistamine?

Answer 22

Pheniramine.

Question 23

Give 2 examples of a short acting 1st gen oral antihistamine?

Answer 23

Dexchlorpheniramine and trimeprazine

Question 24

What are 3 examples of long acting 2nd/3rd generation oral antihistamines?

Answer 24

Loratidine, desloratidine and cetirizine.

Question 25

What is an example of a moderate-duration 2nd/3rd generation oral antihistamine?

Answer 25

fexofenadine

Question 26

What is levocabastine? Describe duration of action, onset of action and bioavailability?

Answer 26

Intranasal antihistamine.
acts within 15 minutes and lasts several hours.
undergoes some systemic absorption, with a bioavailability of about 80%.

Question 27

What is azelastine? what is its duration of action and time till onset?
What is its systemic bioavailability?

Answer 27

fast acting intranasal antihistamine.
effects last for about 12 hours.
40-60% systemic bioavailability.

Question 28

What are the side effects of first generation antihistamines? Can they be used in pregnancy?

Answer 28

Cause sedation and have anticholinergic effects, so dry mouth, thirst etc.
safe in pregnancy.

Question 29

What are the side effects of second/third generation antihistamines? Are they safe in pregnancy

Answer 29

Possible sedation and dry mouth. 1st gen antihistamines are preferred in pregnancy. avoid fexofenadine in pregnancy.

Question 30

What are the side effects of intranasal antihistamines? Are they safe during pregnancy?

Answer 30

local irritation
nose bleeds (rare)
bitter taste (particularly with azelastine)
Pregnancy category B3: prefer 1st gen oral antihistamines.

Question 31

What are some examples of nasal corticosteroids?

Answer 31

beclamethasone
fluticasone
budesonide
tramcinolone
mometasone

Question 32

What is the mechanism of action of nasal corticosteroids?

Answer 32

decrease inflammatory cell migration, reduce T-cell function and proliferation, decrease cytokine production –> vasoconstriction, decreased capillary permeability and decreased mucous production.