Allergic Rhinitis

OTC 2015

References Practice guideline for the treatment of allergic rhinitis. American

Academy of Otolaryngology–Head and Neck Surgery Feb.2015, Vol. 152(1S) S1–S43

Treatment of Allergic Rhinitis. Am Fam Physician. 2010;81(12):1440-1446.

Allergic rhinitis management pocket reference 2008. Allergy 2008: 63: 990–996.

Pharmacotherapy: A pathophysiologic Approach. 7th Edition 2008.

Safety of Antihistamines in Children. Drug Safety 2001; 24 (2): 119-147.

Second-Generation Antihistamines Actions and Efficacy in the Management of Allergic Disorders. Drugs 2005; 65 (3): 341-384

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Allergic Rhinitis-OverviewThe most common atopic diseaseThe hallmark of ~: a temporal relationship

between the exposure to allergens & the development of nasal symptoms

It takes at least 2 years of exposure to aeroallergens (airborne environmental allergens) to develop AR (thus, very rare in children <1 year)

The prevalence of AR: lowest in children < 5 yrs

highest 2nd---- 4th decadesGenetic predisposition (60%)

In a sensitized individual, allergic rhinitis occurs when mucous membranes are exposed to inhaled allergenic materials that elicit a specific response mediated by immunoglobulin E (IgE).

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Definitions.Allergic Rhinitis (AR) is an inflammatory, IgE-mediated disease characterized by nasal congestion, rhinorrhea (nasal drainage), sneezing, and/or nasal itching. It can also be defined as inflammation of the inside lining of the nose that occurs when a person inhales something he or she is allergic to, such as animal dander or pollen; examples of the symptoms of AR are sneezing, stuffy nose, runny nose, post nasal drip, and itchy nose.

AR may be classified by: (1) the temporal pattern of exposure to a triggering allergen, such as seasonal (eg, pollens), perennial/ year-round (eg, dust mites), or episodic (environmental from exposures not normally encountered in the patient’s environment, eg, visiting a home with pets);

(2) frequency of symptoms; and

(3) severity of symptoms. Classifying AR in this manner mayassist in choosing the most appropriate treatment strategies for an individual patient.

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Allergen sensitization and the allergic response. A. Exposure to antigen stimulates IgE production and sensitization of mast cells with antigen specificIgE antibodies. B. Subsequent exposure to the same antigen produces anallergic reaction when mast cell mediators are released.

Mast cells degranulating and releasing vasoactive amines.

Mast Cell Mediators

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Allergic RhinitisMost patients develop symptoms before age

30Asthma develops in about 19% of children

with rhinitis (more likely with perrenial allergic rhinitis)

The term “rhinitis” refers to the inflammation of the nasal mucous membranes. Whenever a a causative allergen can be identified allergic rhinitis

It is difficult sometimes to distinguish between different types of rhinitis

Comparison between different types of rhinitis

Features of Common Rhinitis SymptomsAllergic rhinitis

Infectious rhinitis

Vasomotor rhinitis Rhinitis Medicamentosa

Etiology Allergen Viral or bacterial

Unknown Tachyphylaxis to topical decongestants

Symptoms Rhinorrhea, congestion, sneezing, pruritis, cough with postnasal drip ocular itching etc

Fever (more common in children), mucupurulent rhinorrhea, scratchy throat, congestion, cough

Rhinorrhea, congestion

Congestion

Pattern Perennial or seasonal

Any time Any time Temporal relationship with use of topical decongestant

Associated Factors

Concurrent atopic disease, family history

None Affects women primarily, strong odours, alcohol, stress, change in humidity and temperature

Overuse of topical decongestants, concurrent use of antihypertensive therapy

Perennial Allergic Rhinitis Caused by continuous exposure to many

different types of allergensDust Mite the most common cause of

perennial allergic rhinitisCommonly: household dust mites, molds,

cockroaches, house petsLess commonly: cottonseed & flaxseed (found

in fertilizers, hair setting preparations and foods); some vegetable gums (found in hair setting prep & foods)

Caused by:

Dust mites

Perennial Allergic Rhinitis Dust mite: thrive in carpets, beddings &

reproduce best in warm (18-21ºC) humid (>50%) environment found in most homes

Mites feed on human skin scales and their own faeces.

Mite itself is not allergen, the main allergen is the glycoprotein that coats their faeces.

Dust mite remain airborne for about 30 minutes after being disturbed

Molds: grow best in warm, moist environmentCat-derived allergens: light small proteins

secreted through the sebaceous glands in the skin. May remain airborne for up to 6 hrs. Can be detected at home even 6 months after removal of the cat.

Seasonal Allergic RhinitisCaused by wind-borne plant pollens

(e.g. tree, grass. etc)“hay fever”, and “rose fever” are

terms related to seasons associated grass pollinosis and NOT associated with FEVER!

Complications1. Sinusitis2. Recurrent otitis media & hearing loss3. Patients who develop: fever, purulent nasal discharge, frequent HA, earache

refer to Dr. for evaluation and treatment

Symptoms of Allergic RhinitisOcular: itching, lacrimation, mild soreness,

puffiness & conjuctival erythemaNasal: congestion, watery rhinorrhea, itching,

sneezing, postnasal drip and nasal pruritusHead & Neck: loss of taste and smell, mild

sore throat due to postnasal drip, earache, sinus HA, itching of the palate and throat

Systemic: malaise & fatigue:

Physical Assessment“allergic shiners” venous/lymphatic

congestionChronic mouth breathing highly arched

palateA horizontal crease across the lower third of

the nose (in patients repeatedly rub their noses upward) called “nasal salute”

Nasal mucosa: pale & swollenNasal secretions: clear & wateryEyes: watery with scleral & conjuctival

erythema and periorbital edema

Allergic shiners

Arched palate because of mouth breathing

Periorbital edema

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Update: April 2013The US Food and Drug Administration (FDA) has approved carbinoxamine maleate extended-release (Karbinal ER, Tris Pharma), the first liquid, sustained-release histamine-H1 receptor blocker indicated for the treatment of seasonal and perennial allergic rhinitis in children aged 2 years and older.

The drug will be available in a 4 mg/5 mL oral suspension.It is dosed once every 12 hours, "making it an attractive treatment option" for allergy sufferers who do not respond to second-generation antihistamines and are not satisfied with dosing schedules associated with the first-generation antihistamines.

Carbinoxamine is a mildly sedating antihistamine. Before 2006, it was widely used in carbinoxamine-containing combination products. However, most of these older drugs had not gone through the FDA's approval process.