Allergies Flashcards
Annual direct costs of allergic rhinitis:
$3.4 billion
Indirect costs of allergic rhinitis:
$11 billion
Allergies are triggered by…
indoor and outdoor environmental allergens
Common outdoor allergens:
- pollen
- mold spores
- pollutants (highly populated areas)
Common indoor allergens:
- house dust-mites
- cockroaches
- mold spores
- pet dander
Occupational areoallergens:
- wool dust
- latex
- resins
- biologic enzymes
- organic dusts
- various chemicals
4 phases of pathogenesis:
- sensitization phase
- early phase
- cellular recruitment phase
- late phase
Phase one of pathogenesis: sensitization phase
- occurs on initial allergen exposure
- allergen stimulates beta-lymphocyte mediated IgE production
Phase two of pathogenesis: early phase
- occurs w/in minutes of subsequent allergen exposure
- rapid release of pre-formed mast cells mediators (histamine and proteases)
- includes production of additional mediators: prostaglandins, kinis, leukotrienes, neuropeptides
Phase three of pathogenesis: cellular recruitment phase
circulating leukocytes are attracted to nasal mucosa and release more inflammatory mediators
Phase four of pathogenesis: late phase
- begins 2-4 hours after allergen exposure
- symptoms include mucus hypersecretion secondary to submucosal gland hypertrophy and congestion
- continued persistent inflammation “primes” tissue, results in lower threshold for allergic/nonallergic medicated triggers
Bilateral symptoms are the….
worst in the morning, subside during the day, and then worsen at night
Common symptoms:
- frequent, paroxysmal sneezing
- anterior, watery rhinorrhea
- frequent itching and conjunctivitis
- sinus pain
- throat pain
- allergic shiners
- dennie’s lines
- allergic salute
- allergic crease
- allergic gape
Sinus pain is caused by…
congestion
Throat pain is caused by…
postnasal drip irritation
Allergic shiners are…
darkening around eyes due to venous congestion
Dennie’s lines are…
wrinkles beneath lower eyelids
Allergic salute is…
patient is rubbing tip of the nose upward w/ the palm of their hand
Allergic crease is…
the horizontal crease above bulbar portion of nose secondary to “salute”
Allergic gape:
open-mouth breathing due to nasal obstruction
T/F: allergic rhinitis can be cured
F, can only reduce symptoms and improve patient’s functional status
Treatment should be _______ to provide optimal symptomatic relief and/or control
individualized
Three steps for treatment:
- allergen avoidance
- pharmacotherapy
- immunotherapy
T/F: immunotherapy is only provided by PCP
T
T/F: Allergy avoidance is typically not sufficient for complete relief
T
Avoidance of allergens:
- primary nonpharmacologic measure
- depends on specific allergens
House dust mites:
- found in all but driest regions of US
- thrives in warm and humid environments
How to reduce # of house dust mites:
- lower household humidity to less than 40%
- apply acaricides
- reduce mite-harboring dust by removing items such as: carpet, upholstered furniture, stuffed animals, bookshelves
Outdoor mold spores:
- prevalent in late summer and fall (especially on calm, clear, dry days)
- avoid activities that disturb decaying plant material
Indoor mold spores:
- lower household humidity
- remove houseplants
- venting food preparation areas and bathrooms
- repairing basements or crawlspaces
- frequently applying fungicide to moldy areas
Cat derived allergens:
get allergen free cats :)
How to reduce # of cockroaches:
- keep kitchen areas clean
- keep food sealed
- treat infested areas w/ baits or pesticides
If patients are triggered by pollutants, they need to be aware of…
air quality index (AQI)
- plan for activities when AQI is low
Nasal wetting agents are used to relieve…
- nasal mucosal irritation and dryness
Nasal wetting agents help decrease…
- nasal stuffiness
- rhinorrhea
- sneezing
Nasal wetting agents aids in the removal of ____ from nose
- dried
- encrusted
- thick mucus
Nasal wetting agents include:
- saline
- propylene
- polyethylene glycol sprays
- gels
Nasal irrigation should only be used with…
distilled, sterile, or boiled water
Intranasal corticosteroids are good for…
intermittent/occasional
Intranasal corticosteroids are also known as…
glucocorticords
- considered primary line therapy
Intranasal corticosteroids are effective for treatment of nasal symptoms such as…
- itching
- congestion
- rhinitis
- sneezing
Intranasal corticosteroids inhibit…
multiple cell types and mediators
- stops allergic cascade
Intranasal corticosteroids have low systemic ____
absorption
Adverse effects of Intranasal corticosteroids:
- usually minor
- nasal discomfort
- bleeding
- sneezing
- cough
- pharyngitis
Longterm use of Intranasal corticosteroids has been linked to changes in…
- vision
- glaucoma
- cataracts
- increased risk of infection
- growth inhibition in children
Drug interactions of Intranasal corticosteroids w/…
- protease inhibitors (ritonavir, tipranavir, telaprevir)
- increases serum [ ] of steroids
- avoids combination
Antihistamines are used to relieve…
symptoms of allergic rhinitis
- itching
- sneezing
- rhinorrhea
Mechanism of action of antihistamines:
- compete at central and peripheral histamine-1 receptor sites
- prevents histamine receptor interaction and subsequent mediator release
- 2nd generation antihistamines inhibit release of mast cell mediators as well
- may decrease cellular recruitment
Two classes of antihistamines:
- 1st gen
- 2nd gen
1st generation of antihistamines:
- crosses blood brain barrier
- sedating
- nonselective for H1 receptors
- lipophilic
2nd generation of antihistamines:
- doesn’t cross blood brain barrier
- nonsedating
- peripherally selective for H1 receptors
- lipophobic
Overdose of antihistamines have two effects:
- sedating
- nonsedating
Sedation effects of antihistamines are…
- cardiac symptoms: tachycardia, conduction abnormalities
- CNS signs and symptoms: psychosis, hallucinations, agitation, lethargy, insomnia
Nonsedation effects of antihistamines are…
- drowsiness
- restless/hyperactivity
- tachycardia
Adverse effects of antihistamines:
- primary effects are CNS effects and anticholinergic effects
- mainly seen with 1st gen, rarely with 2nd gen
- anxiety
- hallucinations
- appetite stimulation
Anticholinergic adverse effects:
- dryness of eyes and mucous membranes
- blurred vision
- urinary hesitancy and retention
- constipation
- reflex tachycardia
Drug interactions w/ antihistamines:
- amiodarone
- antacids
- CNS depressants
- metoprolol
- phenytoin
- potassium chloride
Effect of amiodarone and antihistamines:
increased risk of QT prolongation
Effect of antacids and antihistamines:
decrease efficacy
Effect of CNS depressants and antihistamines:
increased sedation
Effect of metoprolol and antihistamines:
increased metoprolol serum [ ]
- risk of hypotension
Effect of phenytoin and antihistamines:
decreased phenytoin elimination
Effect of potassium chloride and antihistamines:
increased risk of ulcers
Contraindicatoins for antihistamines:
- newborns/premature infants
- lactating women
- narrow-angle glaucoma
- stenosing peptic ulcer
- symptomatic prostatic hypertrophy
- bladder neck and pyloroduodenal obstruction
Combination products of antihistamines:
- marketed w/ decongestants and analgesics
- use w/ caution because of increased risk of adverse effects
Indication for decongestants:
- temporary relief of nasal and eustachian tube congestion and for cough associated w/ postnasal drip
- OTC of this are not approved by FDA
Mechanism of action for decongestants:
- stimulation of alpha adrenergic receptors results in constriction of blood vessels
- decreases sinusoid vessel engorgement and mucosal edema
Three types of decongestants:
- direct-acting: bind directly to adrenergic receptors
- indirect-acting: displace norepinephrine from storage vesicles in prejunctional nerve terminals
- mixed: have both direct and indirect activity
Special populations include:
- pregnant women
- lactating women
- children < 12
- elderly patients
First line medication for pregnant women:
intranasal cromolyn
Medications w/ no risk for pregnant women:
- diphenhydramine
- chlorpheniramine
Medications that have low risk of adverse fetal effects:
- levocetirizine
- loratadine
- cetirizine
Medication that has moderate risk of adverse fetal effets:
fexofenadine
T/F: INCS are considered compatible
T
Budenoside and triamcinolone have been linked to…
- cleft lip and palate
- low birth weight
Medications for lactating women:
- intranasal cromolyn
- short acting chlorpheniramine, fexofenadine, or loratadine (best option)
- take dose at bedtime after last feeding of the day
Children < 12 should be referred to PCP for possible…
undiagnosed asthma
Elderly patients should avoid…
sedating histamines
Why should elderly patients avoid sedating histamines?
- increased risk of CNS depressive adverse effects (confusion/hypertension)
- more likely to be taking meds w/ anticholinergic properties
Drugs of choice for elderly patients:
- loratadine
- intranasal cromolyn
Many patients achieve symptomatic relief w/in…
3-4 days of therapy
- complete relief: 2-4 weeks
