Allergic Rhinitis

Risk factors for allergic rhinitis

• upper respiratory system disorders

• family history

• elevated serum IgE > 100 IU/ml prior to age 6

• high socioeconimc levels

• eczema

• positive allergy skin tests

• > 3 fast food meals a week

• unknown mechananism

• maybe related to fatty acids or trans fats

Allergy Triggers

outdoors: aeroallergens, pollen and mold spores

pollutants: ozone, tobacco smoke, diesel exhaust

indoor aeroallergens: dust mites, cockroaches, mold spores, pet dander

occupational allergens: wool dust, latex, resins, biologic enzymes, organic dusts, various chemicals

Pathophysiology is in four phases

1) initial exposure: (sensitization) stimulations of beta-lymphocyte-mediated IgE production

2) within minutes: (early) rapid release of preformed mast cell mediators, production of new mediators

3) over time (cellular recruitment) eosinophils attracted to nasal mucosa and release more inflammatory mediators

4) 2-4 hours post exposure (late) mucus hyper secretion secondary to submucosal gland hypertrophy and congestion

Duration

intermittent: symptoms occur < 4 days per week or < 4 weeks

Persistent: symptoms occur > 4 days per week and > 4 weeks

Episodic: symptoms only occur when individual is in contact with exposure

severity

mild: symptoms do not impair sleep or daily activities, no troublesome symptoms

moderate/severe: one or more of the following occur

• impairment of sleep, daily activities, troublesome symptoms

Signs/symptoms of allergic rhinitis

• bilateral symptoms, worse upon waking

• frequent sneezing

• watery rhinorrhea

• frequent itching of eyes, nose, and palate

• variable nasal obstruction

• Frequent conjunctivitis (red, irritated eyes)

• sinus or throat pain

• allergic shiners (periorbital darkening from venous congestion)

• dennie’s lines (wrinkles on lower eyelids)

• allergic crease (horizontal crease above bulbar portion of nose)

• allergic salute (rubs tip of nose upward with palm)

• allergic gape (mouth breathing)

Non-pharm for allergic rhinitis

dust mites: lower humidity <40%, limit fabric use, encase bedding, wash bedding weekly in hot water

mold spores: avoid disturbing decaying plants, lower indoor humidity, remove house plants, good ventilation in moist areas

pet dander: pet baths, avoid animals

cockroaches: keep kitchen clean, keep food tightly stored, treat infected areas

pollutants: be aware of air quality, plan outdoor activities when AQI is low

pollen: keep up to date on pollen counts, avoid outdoor activities, close windows

Other nonpharm options

• ventilation using high efficiency particulate air filters

  • these remove pollen, mold, and pet allergens

  • not dust mite fecal matter

  • change regularly

• weekly vacuum

• only use distilled, sterile or boiled tap water in nasal irrigation to avoid infection

Exclusions for self treatment for allergic rhinitis

• children < 12 years old

• pregnant or lactating

• symptoms of nonallergic rhinitis

• symptoms of otitis media, sinusitis, bronchitis, or other infections

• symptoms of undiagnosed or uncontrolled asthma or other lower respiratory disorders (wheezing, SOB)

• severe or unacceptable side effects of treatment

pharm therapy for allergic rhinitis

• intranasal corticosteroids

• antihistamines

• decongestants

• cromolyn sodium

Intranasal corticosteroids

glucocorticoids

• effective for itching, rhinitis, sneezing, congestion

• dose = 1-2 sprays in each nostril once daily

AE: nasal discomfort, bleeding, sneezing, cough, dizziness, N & V

MOA: inhibits multiple mediators including histamine (stop allergic cascade)

antihistamines

MOA: compete with histamine at central and peripheral histamine receptor sites (H1), preventing mediator release

• first gen (nonselective)

  • sedating

  • risk of anticholingic side effects

• second gen (partially selective)

  • non-sedating

  • inhibits release of mast cell mediators and may decrease cellular recruitment

First gen antihistamines examples

diphenhydramine (benadryl):

• 25-50 mg Q 4-6 hrs

• 300 mg max daily dose

chlorpheniramine:

• 4 mg Q 4-6 hrs

• 24 mg max daily dose

2nd gen antihistamines

loratadine (claritin):

• 10mg Q 24 hrs

Cetirizine (zyrtec):

• 10 mg Q 24 hrs

Fexofenadine (allegra):

• 180mg Q 24 hr

• 60 mg Q 12 hrs

Levocetirizine (Xyzal):

• 5mg Q 24 hrs

Intranasal antihistamines

Azelastine (astepro):

• 1-2 sprays in each nostril BID

AE: bitter taste, runny nose, HA, sedation possible (use at bedtime)

• only use if oral antihistamine fails

AE of first gen antihistamines

dryness of mucous membranes, blurred vision, urinary hesitancy and retention, constipation, reflex tachycardia

• sedating, may agitate children

• don’t use in newborns, lactating, narrow angle glaucoma, acute asthma, COPD

AE of second gen antihistamines

• usually well tolerated

• may cause sedation

• dryness

Cromolyn Sodium

• treats allergic rhinitis symptoms

MOA: mast cell stabilizer, blocks influx of calcium into mast cells, preventing mediator release

• less than 7% absored systemically

• 1 spray in nostril 3-6 times daily

AE: sneezing, nasal stinging, burning

Pregnancy

if allergic rhinitis is present:

• intransal cromolyn 1st line

• diphenhydramine and chlorpheniramine is good

• levocetirizine, loratadine, and cetirizine low risk of fetal AEs

• fexofenadine is moderate risk

• Intranasal corticosteroids = don’t give can cause cleft lip and low birth weight

Lactating women

• intranasal cromolyn 1st line

• intranasal corticosteroids are good

• no antihistamines

Children < 12 years old

• refer due to risk of undiagnosed asthma

if approved by physician for OTC:

• cromolyn, fluticasone furoate, triamcinolone > 2 years old

• fluticasone propionate > 4 years old

• budesonide > 6 years old

• loratadine is antihistamine of choice

• no 1st gen antihistamines

Older adults

• no 1st generation antihistamines

• cromolyn and loratadine are drugs of choice

• fexofenadine and levocetirizine need renal dose adjustment

• loratadine and cetirizine need renal and hepatic dose adjustment