Allergic Rhinitis Flashcards
(73 cards)
Rhinitis
Inflammation of the lining of the nose and other parts of the upper respiratory tract.
Most common is allergic rhinitis: allergen induced and IgE mediated, releases inflammatory markers.
Allergic rhinitis
Seasonal (hay fever) versus Persistent (perennial rhinitis)
Seasonal allergic rhinitis
Specific, seasonal allergies. Predictable times of the year. Pollen from trees, grasses and weeds.
Perennial rhinitis
Non-seasonal allergens. Year round, or specific months throughout the year. Dust mites, animal dander, molds. Less variable, chronic symptoms.
AR risk factors
Genetics, family history, exposure to allergens, IgE >100 before age 6, eczema, heavy secondhand smoke exposure, higher socioeconomic status.
Protective: exposure to harmless microbes in first year of life.
Pathophysiology of the nose
Heating, humidification, filtration.
Air moves through the nose, particulate matter sticks to the mucous membrane, cilia moves mucous towards throat, trapped particles are swallowed and excreted by GI tract.
Concentrates foreign proteins in the nasopharynx, identification by lymph system, produces allergic antibodies, allergic rhinitis occurs.
Immediate phase of AR
Within minutes, mast cell degranulation. Release of pro-inflammatory mediators (histamine, cytokines), release of inflammatory mediators (leukotrienes, prostaglandins, bradykinin).
Nerve stimulation: nasal itching, sneezing
Histamine: nasal drainage and obstruction
Late phase of AR
4-8 hours after allergen exposure in 50% of patients.
Cytokines released by mast cells and T lymphocytes migrate to site of allergen exposure.
Nasal congestion: primary characteristic of the late phase and can be persistent and chronic.
AR signs
Allergic salute: crease on nose
Allergic shiners: bags under eyes
Mouth breathing
Symptoms: rhinorrhea, post-nasal drip, sneezing, itchy eyes, ears, nose, red, watery eyes.
Complications of AR
Poor performance, malaise, asthma, acute otitis media, chronic middle ear infections, lack of sleep, sinusitis, vocal polyps and hearing problems.
AAAA/ACAAI classifcation
Seasonal: symptoms present during specific portion of the year
Perennial: symptoms present throughout the year
Episodic: symptoms present only during intermittent exposure to allergen trigger
Classification on intermittent/persistent
Intermittent: <4 days a week or <4 consecutive weeks.
Mild: symptoms do not interfere with sleep, school, or daily activities.
Moderate/severe: impairment of sleep, impairment of daily activities or school/work, troublesome symptoms.
Persistent: >4 days a week or >4 consecutive weeks.
Mild: same as above
Moderate/severe: same as above
Treatment goals
Minimize frequency and severity of symptoms, improve QOL, prevent complications, improve attendance/performance, minimize adverse effects of therapy.
Approaches to treatment
Allergen avoidance, pharmacotherapy, immunotherapy
Non-pharmacologic therapies
Breastfeed infants exclusively for 3 months, avoid environmental secondhand smoke, attempt environmental control by avoiding allergens, consider the use of nasal saline.
Nasal saline
Moisten nasal cavity and promote mucocilliary clearance. Alternative or adjunct to treatment. Irrigation, spray, drops or neb. Relief of sneezing, nasal congestion. Can cause nasal irritation, infection. Use purified water.
Antihistamines
H1 receptor antagonist: competitive antagonist to histamine. Binds to H1 receptor without activating them, prevents histamine from binding and causing effects.
First generation antihistamines
Non-selective, sedating.
OTC: Chlorpheniramine, Clemastine, Diphenhydramine
SE: sedation, dry mouth, dry eyes, urinary retention
Second generation antihistamines
Peripherally selective, non-sedating.
OTC: Zyrtec, Allegra, Claritin.
SE: Less likelihood of sedation
Ophthalmic antihistamines
Can be used with or without nasal steroids for ocular symptoms.
Bepotastine (Bepreve)
Azelastine (Optivar)
Ketotifen (Alaway/Zatidor)
Olopatadine (Pataday/Patanol)
Intranasal antihistamines
Consider for seasonal allergic rhinitis. Rapid symptom relief.
SE: drowsiness, drying effects, headache, tolerance.
Azelastine Olopatadine (selective H1, less drowsy)
Decongestants
Topical, systemic. For nasal congestion.
Alpha adrenergic receptor agonist on nasal mucosa, cause vasoconstriction.
Shrinks swollen mucosa, improves ventilation.
Phenylephrine (alpha 1)
Oxymetazoline and naphazoline (alpha 2)
Pseudophedrine (a and norepi)
Topical decongestants
Max 3-5 days, rebound congestion.
Use smallest dose, use infrequently, use only when necessary.
Adverse effects: burning, stinging, dryness, sneezing.
Minimal systemic effects, decreased blood pressure effects (compared to systemic ones)
Phenylephrine (Neo-Synephrine)
Nasal decongestant. Short acting, up to 4 hours. Alpha 1.
