Allergic Rhinitis Flashcards
Describe the allergic process
- Allergic response to allergens (proteins)
- Mast cells exist at body interface (stomach, eyes, skin)
- Initial exposure –> No rxn however leads to sensitization
- Subsequent exposure enacts symptoms via mast cells release of mediators 9e.g. histamine)
What is sensitization?
Sensitization = your body has seen this before and now stands ready. The mast cell now has receptors ready to pick up the allergen when it next appears (allergy season)
Early Phase vs. Late Phase RXN
Early –> Rhinorrhea, itchiness, maybe some sneezing
late –> oedema and congestion
What is the link between asthma and allergies?
Some component of allergic rhinitis . If can’t control one, other gets worse. Need to have control of both.
Is anti-histamine effective for all mediators?
No
can control histamine; however, other receptors activated and mediators released
Perennial Allergies
- Year round; all the time
Acute Allergies
- Can be long; but after 2 months stops –> Seasonal
What are some differentials?
Vasomotor rhinitis (temp)
Rhinitis Medicamentosa (decongestants-rebound)
Hormonal (birth control)
geriatric Rhinitis
How is allergic rhinitis classified (new)?
Intermittment - Less than 4 days per week, or less than 4 weeks at a time
Persistent - Greater than 4 days per week and greater than 4 weeks at a time
Mild –. Normal sleep, normal activities
Moderate-severe –> Abnormal sleep, impairement of daily activities
Common symptoms of allergies
Sneezing, rhinorrhea, congestion, itchy eyes, nasal drip
Facial cues of allergic rhinitis
- Puffy eyes, mouth breathing
Allergies vs a cold
- same time every summer
Increase sneezing and itchiness
Runny nose and congestion
Last longer
PND
More ocular
Avoidance of Alergens
- Very hard to do
Nasal irrigation
Well tolerated
Small benefit
- helps flush out allergens
Nasal Sprays
- not the same as irrigation
- tortured by irritation; lubrication can provide relief
- can use long term
Anti-histamines MOA
H1 –> Mast Cells –> prevent histamine release
H2 –. Stomach
How should anti-histamines be used for optimal effectiveness?
- Best used prior to allergen exposure
Regular dosing is bttter than prn use
When would a topical steroid be more useful?
- Topical steroid better for congestion phase than antihistamine
First genration ANti-histamines
Promethazine
ETHANOLAMINES:
diphenyhydramine
doxylamine
clemastine
ALKYLAMINES
chlorpheniramine
brompheniramine
debroxmpheniramine
tripolidine
1st gen sedation
promethazine > ethanoamines > alkylamines
What are some symptoms of anti-histamines?
- Block H1 receptors alows blockage of cholinergic receptors
- Anticholinergic symptoms –> dry mouth, drowsiness, constipation
1st Gen in Kids and Older People
Kids –> Avoid –> use 2nd gen –> Does not cause paradoxical excitation
Avoid in elederly
Second Genration ANti-histamines and age of use
Loratidine - 2
Desloratidine - 2
cetrizine - 2
Fexofenadine - 12
Interactions 2nd gen
- Fexofenadine + grapefruit/orang/apple juice and when taken with food
Why are 2nd gen better than first gen?
- Higher affinity for receptor
- Less s/e
- Not sedating
Patient Dynamics
- Little chance for complete relief
- Expect trial and error
Intranasal Antihistamines
- Dristan - phenylephrine and pheniramine
Dymista - flucatisone (topical steroid) and azelastine
Ocular Anti-histamines
OTC
pyrillamine, antazoline, pheniramine
RX
Emedastine, ketotifen
Decongestant and Anti-histamine
- Want them seperate
Intransal Steroid Examples, safety and Use
Mometasone
Flucatisone
Ciclesonide
- Safe –> Will not get rebopund congestion
When we put the in the nose, do not see common steroidal effects as on the skin –> unheard of –> no mucosal thinning - Useful for congestion
- Budesonide
-Beclomethasone - Flunisolide
Efficacy and Onset of ACtion of Intransal Steroid
- More effective than 2nd gens
- Gonna need 2 weeks to get onset of action (will get some relief in first few days)
Intransal Steroids Dosing, S/e and duration of therapy
- OD or BID
- regular use is better
- S/e –> Local irritation, nose bleeds (epitaxis), spray runs down back of throat
- Can use for 2 years; take drug holidays
Ages for Intransal Steroids
- Go with what label says
Directions for Intransal Steroid Use
- Shake and Prime (makes sure you get ful dose)
- Blow nose
- Look down
- Use right hand for left nostril and vice versa
- Spray to outside of nose wall
- Do not sniff hard
Cromolyn
- Mast cell stabilizer –> prevents mediator reease
- Cromolyn, Nalcrom, Opticrom
Dose frequently
Opthalmic Allergies
- Therapeutics for eye often underdosed
- Mast cell stabilizers:
Cromolyn
Alocri
Patanol
Alomide
Immunotherapy
- Allergy shots
- Really bad allergies
Montelukast
Lukotriene antagonist
- Asthma, allergic rhinitits
- Add on therapy
Ipratropium
- anti-cholinergic mechanims
Used in vasmotor rhinitis therapy
Allergies Pregnancy
Nasal Congestion Common
- MD realm
1st gen and 2nd gen appear to be safe
Anti-histamines and Intranasal steroids in Asthma
Avoid 1st gen, 2nd gen of choice
Patient is on inhaled steroid, adding an intranasal steroid is reasonable
Children ANti-histamines
- 1st gen safe; however use second gens
- newer topical steroids are safe –> no negative growth effects
