CPP 2 (Allergic Rhinitis)

Allergic rhinitis

involves inflammation of nasal mucous membranes in sensitized individuals when inhaled allergenic particles contact mucous membranes

immunoglobulin E (IgE)

Allergic rhinitis is elicits a response mediated by __________

red itchy and watery eyes

sneezing congestion and runny nose

itchy or sore throat

cough and postnatal drip

Itchy ears and buzzing sound

common symptoms of allergic rhinitis (5)

Seasonal (hay fever) allergic rhinitis

occurs in response to specific allergens (pollen from trees, grasses, and weeds) present at predictable times of the year and typically causes more acute symptoms.

Persistent allergic rhinitis

occurs year-round in response to nonseasonal allergens (eg, dust mites, animal dander, and molds) and usually causes more subtle, chronic symptoms

Airborne allergens

enter the nose during inhalation and are processed by lymphocytes, which produce antigen-specific IgE, sensitizing genetically predisposed hosts to those agents

First exposure

nasal reexposure IgE bound to mast cells interacts with airborne allergens, triggering release of inflammatory mediators.

histamine, leukotrienes, prostaglandin, tryptase, and kinins.

Mediators of immediate hypersensitivity include

prostanoid and leukotriene, immediate reaction (seconds to minutes)

arachidonic acid cascade forms what? and what reaction does it induce

4 to 8

A late-phase reaction in AR may occur __to_ hours after initial allergen exposure due to cytokine release from mast cells and thymus-derived helper lymphocytes.

persistent chronic symptoms

A late phase allergic rhinitis causes

dark circles under the eyes (allergic shiners)

In children, physical examination for AR may reveal

asthma

Allergic rhinitis is associated with ______ 10% to 40% have this

Avoidance of allergen

this is the core component of therapy which is hard in presistent formerly known as perennial

single drug treatment

if allergen is not totally avoided " ___________" is used based on symptom

montelukast or immunotherapy

if symptoms is still not controlled what should be considered

Medical history

includes careful description of symptoms, environmental factors and exposures, results of previous therapy, use of medications, previous nasal injury or surgery, and family history.

Skin Prick testing, Blood tests for total IgE level [RAST test] and/or eosinophil count, and Nasal smear test

Diagnostic tests for allergic rhinitis (4)

abiding offending allergens

most important non pharmacologic treatment

H1 receptor

Antihistamines inhibits what receptor

Antihistamine

H1-receptor antagonists bind to H1 receptors without activating them, preventing histamine binding and action. They are effective in preventing the histamine response but not in reversing its effects after they have occurred

nonselective (first-generation or sedating antihistamines) and peripherally selective (second-generation or nonsedating antihistamines).

Oral antihistamines are divided into two categories

1 to 2

Antihistamines are more effective when taken ___ to ___ hours before anticipated exposure to offending allergen

piperazine and piperidine

(2) second generation antihistamine classification

second generation piperadine

the true non sedating classification of antihistamine

Decongestants (topical and systemic)

are sympathomimetic agents that act on adrenergic receptors in nasal mucosa to produce vasoconstriction, shrink swollen mucosa, and improve ventilation

Phenylephrine, Tetrahydrozoline, Na phazoline, Oxymetazoline, and Xylometazoline

example of Topical decongestants

Rhinitis medicamentosa (rebound vasodilation with congestion)

may occur with prolonged use of topical decongestant agents (>3–5 days)

abrupt cessation

is an effective treatment for rhinitis medicamentosa

burning, stinging, sneezing, and dryness of the nasal mucosa.

adverse effects of topical decongestants (4)

Pseudoephedrine and phenylephrine

Example of systemic decongestants

Nasal corticosteroids

relieve sneezing, rhinorrhea, pruritus, and nasal congestion with minimal side effects. similar to ICS but nasal. These agents are an excellent choice for persistent rhinitis and can be useful in seasonal rhinitis, especially if begun in advance of symptoms.

Cromolyn sodium (Nasalcrom)

a mast cell stabilizer, is available as a nonprescription nasal spray for symptomatic prevention and treatment of allergic rhinitis.

sneezing and nasal stinging

Cromolyn sodium (Nasalcrom) most common side effect

Ipatropium bromide (Arovent)

is an anticholinergic agent nasal spray useful in persistent allergic rhinitis. It exhibits antisecretory properties when applied locally and provides symptomatic relief of rhinorrhea

Montelukast (Singulair)

is a leukotriene receptor antagonist approved for treatment of persistent allergic rhinitis in children as young as 6 months and for seasonal allergic rhinitis in children as young as 2 years.

Immunotheraphy

is the slow, gradual process of injecting increasing doses of antigens responsible for eliciting allergic symptoms into a patient with the intent of inducing tolerance to the allergen when natural exposure occurs.

avoidance and nasal administration of saline

non pharmacologic treatment of allergic rhinitis (2)

INCS and oral or intranasal antihismaine

routine first line agent for treatment of allergic rhinitis

oral antihistamine preferably second gen

First line medication for mild intermittent AR

Intranasal corticosteroid, may add oral antihistamine

First line medication for persistent or moderate-severe AR

Oral antihistamine

treatment for episodic AR

Allergen specific immunotheraphy (SIT)

involves repetitive dosing of allergen(s). – SIT can be done via subcutaneous immunotherapy (SCIT) or sublingual immunotherapy (SLIT). The major advantage of SLIT over SCIT is ease of administration

Cetirizine and Levocetirizine

give 2 example of peripherally selective anti histamine

Desloratadine

Fexofenadine

Loratadine

Olopatadine (nasal and ophthalmic only)

give 4 examples of peripherally selective piperidine class antihistamine

1st generation Ethanolamine class non-selective

the most sedating classification of antihistamine