9 & 10 - Allergic Rhinitis Flashcards
What causes allergic rhinitis? What does this result it?
- Inhaled allergens
- Results in mucosal inflammation and airflow obstruction
What is allergic rhinitis characterized by?
Nasal sx of sneezing, pruritus, and discharge
What are some conditions that often occur w/ allergic rhinitis?
- Asthma
- Sinusitis
- Otitis media
- Conjunctivitis
What is allergic rhinitis classified as?
Major chronic respiratory disease
What are the major risk factors associated w/ allergic rhinitis?
- Age (most prevalent in adolescents and young adults)
- Family history
- Repeated exposure to multiple offending allergen
- Presence of other allergic conditions (asthma, atopic dermatitis)
What is the typical onset age of allergic rhinitis?
10 y/o
What is the pathophys of allergic rhinitis?
1) Sensitization - IgE produced binds to mast cells and basophils
2) Immediate reaction - recognition of allergen by IgE bound to mast cells and basophils causes degranulation, releasing preformed mediators (histamine, TNF, leukotrienes); happens w/in mins of re-exposure and lasts for 30-90 mins
3) Late reaction - migration of inflammatory cells, eosinophils, monocytes, macrophages, and basophils; occurs 4-8 h after exposure
What happens w/ repeated exposure to an allergen?
Inflammation “primes” the tissue, decreasing threshold of allergen required to produce an immediate response
What are common ocular sx of allergic rhinitis?
- Red, irritated eyes w/ prominent conjunctival blood vessels
- Itching or burning
- Tearing
- Stringy or watery discharge
- Puffy eyelids, especially in morning
What are some facial features of allergic rhinitis?
- Allergic gape (open mouth breathing secondary to nasal obstruction)
- Allergic salute (children wiping runny nose w/ bottom of palm)
- Allergic shiners (periorbital darkening secondary to venous congestion)
- Dennie’s lines (wrinkles beneath lower eyelid)
What are some systemic sx of allergic rhinitis?
- Cognitive impairment
- Fatigue
- Irritability
- Malaise
What are the various characterizations of allergic rhinitis?
- Seasonal, perennial (all year), or episodic
- Intermittent or persistent
- Mild or moderate to severe
What determines if allergic rhinitis is intermittent or persistent?
Persistent is more than 4 days per week and more than 4 weeks per year; intermittent is 4 or less
What determines if allergic rhinitis is mild or moderate to severe?
- Mild = has sx, but doesn’t interfere w/ QOL
- Moderate to severe = sx interfere w/ QOL
What are differential diagnoses for allergic rhinitis?
- Infectious rhinitis (viral, common cold)
- Idiopathic non-allergic or vasomotor rhinitis (non-inflammatory)
- Hormonal rhinitis (pregnancy, menstruation)
- Non-allergic inflammatory rhinitis
- Occupational rhinitis
- Nasal polyps
- Drug-induced rhinitis
What is vasomotor rhinitis? Symptoms?
- Non-allergic rhinitis, w/ onset later in life
- Sx = nasal congestion, rhinorrhea, and postnasal drip
What are triggers for vasomotor rhinitis?
- Temp
- Exercise
- Environmental changes
- Cigarettes
- Perfume
- Emotional stress
What are some medications that can cause non-allergic rhinitis or drug-induced rhinitis?
- Antihypertensive agents (prazosin, beta-blockers, ACE inhibitors)
- Oral contraceptives
- NSAIDs
- Overuse of topical decongestants
- Older antipsychotic agents
What are some red flags for allergic rhinitis?
- Under 2 y/o
- Wheezing and SOB
- Tightness of chest
- Painful ear or sinuses
- Fever
- Purulent nasal or ocular discharge
- Allergen not identifiable
- Impaired QOL
What are some non-pharms for allergic rhinitis?
- Avoid allergen
- Normal saline
- Nasal breathing strips
What is the purpose of nasal saline?
- Reduces nasal concentration of inflammatory mediators, possibly helping to prevent or eliminate congestion
- Flush out mucous and allergens
- Improve nasal airflow
How do nasal breathing strips work?
Improve nasal airflow in px suffering from congestion
What is the mechanism of antihistamines?
- Competitive, reversible antagonist at H1 receptor
- Prevents histamine binding
What symptoms of allergic rhinitis can antihistamines reduce?
- Sneezing
- Rhinorrhea
- Itch (nasal, palatal, ocular)
- Nasal congestion and/or stuffiness (only desloratidine, cetirizine, and fexofenadine)
What is the tx of choice for mild sx of allergic rhinitis?
2nd gen antihistamines
What are the 1st gen antihistamine?
- Chlorpheniramine
- Diphenhydramine (benadryl)
- Brompheniramine/ doxylamine/ triprolidine/ pyrilamine (Nyquil)
What are the 2nd gen antihistamines?
- Loratidine
- Cetirizine
- Fexofenadine
What is the 3rd gen antihistamine?
Desloratidine
What are adverse effects of 1st gen antihistamines?
- Dry mouth and eyes
- Constipation
- Sedation
- Fatigue
What are drug interactions w/ 1st gen antihistamines?
- Alcohol
- Hypnotics
- Sedatives
- CNS depressants
What are adverse effects of 2nd gen antihistamines?
- May cause drowsiness in some
- Headache
When should cetirizine be avoided?
If have hypersensitivity to hydroxyzine
When should antihistamines be taken?
Before exposure to allergen, b/c prevent actions of histamine (can’t reverse effects of histamine after it has been activated)
What should be done if antihistamines are ineffective?
As long as no adherence issues, px can switch to another class of antihistamine
Which antihistamines are available as IM dosage form?
1st gen
What are the general recommendations for antihistamines?
- Start tx 10-14 days before onset of sx (for seasonal/intermittent allergies)
- Continue throughout season and for 2-3 weeks after season
- Take on daily basis for chronic sx
- For infrequent exposure, take AH 2-5 hours before exposure
Which groups of px should avoid products w/ anti-cholinergic side effects (ex: 1st gen antihistamines)?
- Glaucoma (will increase intraocular pressure)
- Arrhythmias (will increase heart rate)
Can antihistamines be used in hypertension?
Yes, as long as no other conditions
What are contraindications for 1st gen antihistamines?
- Glaucoma
- Severe bladder obstruction
- Stenosing peptic ulcer
- Hyperthyroidism
- Cardiac disease (heart failure, ischemic heart disease)
- Prostate disease
- Chronic lung disease
What are the oral decongestants?
- Phenylephrine
- Pseudoephedrine
What are the intranasal decongestants?
- Oxymetazoline
- Xylometazoline
- Phenylephrine
How do decongestants work?
- Vasodilate capillaries that cause congestion
- Vasoconstrict alpha receptors in nasal mucosa and decrease inflammation
Which decongestant is an alpha 1 agonist?
Phenylephrine
Which decongestants are alpha 2 agonists?
- Oxymetazoline
- Xylometazoline
Would a decongestant improve nasal itching, sneezing, or runny nose?
No
What is the onset of oral decongestants? What is the age limit?
- 15-30 mins
- Used in px 6 y/o and older
What are adverse effects of pseudoephedrine?
- Irritability
- Dizziness
- Headaches
- Insomnia
What are contraindications to oral decongestants?
- Heart disease, severe hypertension, coronary artery disease
- Angle-closure glaucoma
- Diabetes
- Hyperthyroidism
- Prostate enlargement
Which drugs interact w/ oral decongestants?
- MAOIs
- TCAs
- Methyldopa
What is the onset of intranasal decongestants?
5-10 minutes
What is the dosing for each intranasal decongestant?
- Oxymetazoline = q12h
- Phenylephrine = q4h
- Xylometazoline = q8-10h
What are side effects of intranasal decongestants?
- Nasal burning
- Stinging
- Dryness
- Mucosal ulceration
- Rhinitis medicamentosa (rebound congestion)
What is the age restriction for intranasal decongestants?
12 y/o and older
What is the contralateral technique for intranasal decongestants?
Block one nostril and spray into nose w/ other hand
When are ophthalmic decongestants used?
In combination w/ antihistamines to relieve conjunctivitis
What is the mechanism of ophthalmic decongestants?
Vasoconstriction, resulting in decrease of eye redness
What is a contraindication for ophthalmic decongestants?
Angle closure glaucoma
What are side effects of ophthalmic decongestants?
Burning, stinging
Do ophthalmic decongestants produce a rebound effect?
Yes, increases redness and swelling if used more than 10 days
What are examples of ophthalmic decongestants?
- Naphazoline
- Phenylephrine
- Tetrahydrazoline
- Oxymetazoline
What is an example of a mast cell stabilizer?
Sodium cromoglycate
What dosage forms are mast cell stabilizers available as?
- Intranasal spray
- Ocular drops
What is the mechanism of mast cell stabilizers?
- Inhibits degranulation of mast cells
- Doesn’t have antihistamine, anti-cholinergic, or anti-inflammatory effects
What sx do mast cell stabilizers alleviate?
Runny nose, nasal itching, sneezing
What are disadvantages to mast cell stabilizers?
- Delayed onset of action (may take 4-7 days for improvement and 3-4 weeks for full benefit)
- 2-4 sprays TID-QID
Are mast cell stabilizers more effective than antihistamines?
No
What is the mechanism of intranasal corticosteroids?
- Decrease influx of inflammatory cells
- Inhibits release of cytokines, which leads to reduction of inflammation
What is the onset of intranasal corticosteroids?
- Onset w/in 6-8 hours
- Maximal effect in 7-14 days
What are the most effective agents for allergic rhinitis?
Intranasal corticosteroids
When are intranasal corticosteroids the first line therapy?
Moderate to severe or persistant allergic rhinitis
Should intranasal corticosteroids be used prn or continuously?
More effective if used continuously
Are combinations of oral antihistamines and intranasal steroids more effective than each alone?
No
What are side effects of intranasal corticosteroids?
- Burning
- Stinging
- Nosebleeds
- Headache
- Throat irritation
- Nasal dryness
What are the 2 OTC intranasal corticosteroids available?
- Triamcinolone
- Fluticasone
What is the schedule of triamcinolone nasal spray?
- Schedule 3 for 12 y/o and older in packaging that contains no more than 120 sprays
- Schedule 2 if contains more than 120 sprays
- Schedule 1 if for children under 12 y/o
What is the dosing of triamcinolone?
- Initial = 2 sprays in each nostril once daily
- Once maximal benefit achieved, reduce dose to 1 spray in each nostril once daily for maintenance
What is the schedule of fluticasone?
- Schedule 3 for 18 y/o and older in packaging that contains no more than 120 sprays
- Schedule 1 for children under 18 y/o
What is the dosing of fluticasone?
- Week 1 = 2 sprays in each nostril once daily
- Week 2 to 3 months = 1 spray in each nostril once daily if sx controlled
- After 3 months, confirm w/ HCP if continued use needed
What drugs does fluticasone interact w/?
- Ritonavir
- Ketoconazole
- ASA
What are some contraindications for intranasal corticosteroids?
- Immunodeficiency
- HIV medications
- Any signs or sx of infection in nasal cavity
- Oral corticosteroid
- Pregnant or breastfeeding
What is the efficacy of intranasal antihistamines?
- Similar efficacy to oral antihistamines for sx relief of rhinitis and conjunctivitis
- Less effective than INS
What are intranasal combination products? When are they indicated?
- Intranasal combination of corticosteroid and antihistamine
- Indicated when no or incomplete resolution of sx w/ INS alone
What is an example of an intranasal anticholinergic?
Ipratropium solution
What is the mechanism of intranasal anticholinergics?
Prevents secretions of nasal mucosa
What are side effects of intranasal anticholinergics?
- Dryness of nasal mucosa
- Nosebleeds (epistaxis)
- Dry mouth or throat
- Headache
When are intranasal anticholinergics indicated?
- Rhinorrhea only sx or refractory rhinorrhea
- Some types of vasomotor rhinitis
When would oral steroids be used for allergic rhinitis?
- Short time (5-10 days) in px w/ severe sx of allergic rhinitis
- Used in combination w/ INS
Which agent is recommended for persistent sx that affect quality of life?
Intranasal corticosteroids
Which agent is recommended for mild intermittent sx?
Oral 2nd gen antihistamines
What is immunotherapy? When is it indicated?
- Giving the px some of the allergen so when the px is exposed to the allergen in the environment, the immune system won’t respond
- Indicated for moderate or severe persistent allergic rhinitis when usual tx have failed, px doesn’t want medication long term, or px has allergic asthma
What are the 2 types of immunotherapy available?
- Subcutaneous injection, given at regular intervals at doctor’s office
- Sublingual, first dose given at doctor’s office then px takes medication at home daily
How long is immunotherapy taken? How long do the results last?
- Taken for 3-5 years
- Results last 7-12 years
What agents are recommended for allergic rhinitis in children over 2 y/o?
- Most 2nd gen antihistamines
- Fexofenadine can only be used in children over 12 y/o
- Intranasal glucocorticosteroid can be prescribed in children over 4 y/o
Why aren’t 1st gen antihistamines recommended for children?
Can cause hyperactivity
Can mast cell stabilizers be used in children?
Yes
Can decongestants be used in children under 6 y/o?
No, so normal saline can be used to help clear nose
What is recommended for allergic rhinitis in pregnancy?
Loratidine or cetirizine
Can intranasal corticosteroids be used in pregnancy?
Under physician supervision
What type of rhinitis is common in elderly? What is the recommended tx?
- Non-allergic rhinitis
- Intranasal ipratropium recommended for runny nose
What can reduce the effectiveness of fexofenadine?
Grapefruit, orange, and apple juice
When should a px be referred who is taking a systemic decongestant?
If congestion doesn’t improve after 5-7 days
What is the monitoring for allergic rhinitis?
- Symptomatic relief w/ initial OTC therapy in 3-4 days
- Complete relief of sx may take 2-4 weeks (follow-up after 1 week)
- Ophthalmic antihistamines should cause sx resolution w/in 72 hours
What are some non-pharms for allergic conjunctivitis?
- Avoid allergen
- Cold compresses for 10-15 min TID-QID to help redness and itching
What are the pharm options for allergic conjunctivitis?
- 1st line = ocular lubricants for sx relief
- 2nd gen oral antihistamines to stop itching
- 2nd line = ocular antihistamines, ocular decongestants, or decongestant/antihistamine combinations
What is the dosing for ocular lubricants?
1 drop 2-6 times daily
What is the mechanism of ocular lubricants?
- Dilutes allergen and decreases allergen contact time w/ conjunctiva
- Creates barrier against pollens
Can mast cell stabilizers be used for allergic conjunctivitis?
Yes to prevent redness, itching, and eyelid edema
What is the mechanism of ophthalmic decongestants?
Reduces eye redness and eyelid edema through vasoconstriction
What are the 2 available OTC ophthalmic decongestants?
- Phenylephrine
- Imidazolines
What are some precautions w/ ophthalmic decongestants?
- Risk of rebound ocular congestion w/ continued use (more than 10 days)
- Contraindicated in angle-closure glaucoma
What is the monitoring for allergic conjunctivitis?
- Monitor daily for improvement of sx (itching, tearing, redness)
- Refer if no improvement w/in 3 days or sx remain despite tx
