Ramesh Parajuli MSLecturer, Department of Otorhinolaryngology, Head & Neck Surgery

Chitwan Medical College Teaching HospitalBharatpur-10, Fax: 977-56-532937, Chitwan, Nepal

drrameshparajuli@gmail.com

Allergic rhinitis

Definition “IgE mediated hypersensitivity disease of mucous membranes of

nasal airways characterized by sneezing, watery nasal discharge , itching and nasal obstruction” (Durham, 1999)

Prevalence

• Global health problem

• Prevalence - 15% and 20% (Nathan et al.,1999)

• Higher in pediatric age group(Wright et al.,1994)

• Approx. 80% develop symptoms before age of 20 (Skoner et al., 2001)

• Not a severe disorder but significantly alters patient’s social life

-school performance

-work productivity

• Substantial cost

Impact on quality of life

1. Genetic susceptibility:

2. Family history of atopy: e.g. asthma,eczema,hay fever,urticaria

(Genes involved in atopy - loci on 5q,11q and 12q chromosomes)

3. Environmental factors:

• Pollution-climate interaction

• Irritants

eg. fumes, tobacco smoke, diesel exhaust, mosquito repellents, perfumes, scented sticks, domestic sprays, bleaches

4. Exposure to allergens:

• Seasonal : Pollen, Fungus

• Perennial: Dust mite, domestic pets, cockroaches

Risk factors

5.Hygiene hypothesis• Increased exposure to various allergensimmune maturationhelp decrease

the incidence of allergic diseases and asthma (Svanes C et al., 2003)

• Early environmental exposure to infectious agents, protects against development of atopy (Tulic MK et al.,2003)

• Early nursery attendance also reduces subsequent atopy (Kramer et al.,2003)

• Lack of immune maturation (understimulated immune system) in infancyallergic responses (Liu A,2007)

Pathogenesis

• Sensitization & Priming to specific antigen:

Inhaled allergen produces specific IgE antibody

which gets attached to mast cells

• Subsequent exposure to same antigen:

Allergen combines with specific IgE antibody

degranulation of mast cells chemical mediators

released

Acute or early phase response

• Occurs 5–30 min after antigen exposure

• Release of inflammatory mediators

Increased nasal gland secretion runny nose

Mucosal edema & Vasodilation nose block

Nerve irritation sneezing & itching

Late or delayed phase response

• Occurs 2-8 hours after antigen exposure

• Infiltration by inflammatory cells

(eosinophils, neutrophils, basophils,

monocytes & CD4+ T lymphocytes)

• Edema, congestion & thick nasal secretion

• Sneezing & itching decreases

Symptoms

1. Running

2. Blocking

3. Sneezing

4. Itching

Signs Nasal crease Pale turbinate

Face:

• Bunny nose-frequent twitching of face

• Dennie-Morgan creases (in lower eyelid skin)

• Allergic shiners (dark discoloration below lower

eyelids)

Eye: Conjunctiva is congested, increased lacrimation

Ear: Aural fullness(ET dysfunction)

Throat: Chronic pharyngitis, laryngitis

Types of allergic rhinitis

• Seasonal allergic rhinitis:

Nasal discharge and conjunctivitis (more common)

• Perennial allergic rhinitis:

Nasal blockage (more common), Hyposmia

Less sneezing/nasal discharge /eye symptoms

ARIA classification= Allergic Rhinitis & its Impact on Asthma

Rhinitis Rhinitis

Pollen:Spring (March-June) = Tree pollen

Summer (May-August) = Grass

Fall (August-October) = Weeds

Mold:Spores in outdoors have seasonal

variation (reduced in winter, increased in

summer/fall due to humidity)

House dust mites:Generally “perennial” allergen,

but increased in damp autumn months

Seasonal allergic rhinitis

Perennial allergic rhinitis

Fungi/mold:Exposure peaks accompany activities

such as harvesting & cutting grass

Pet dander (cats, dogs):up to 4 months after pet removal

House dust mites:Live in bedding & carpets

Cockroaches:Respiratory allergy

Important allergen

Diagnosis

1.History

2.Physical exam

3.Allergy diagnosis

(I) Skin prick test (SPT)

(II) Blood tests for allergy: Total IgE, Specific IgE

(III) Nasal allergen challenge test

History

I. Skin prick test (SPT)

• Rapid, efficient & cost effective

• Contain multiple antigens

(pollen, mold, dust mite, animal dander)

Skin Prick test

Advantages:

1. Cheap

2. Immediate result

3. Sensitive

Contraindications:

1. Patients on antihistamines

2. Severe eczema

3. Previous anaphylaxis

4. Dermagraphism

(II) Blood tests for allergy

1.Total IgE:

Rarely helpful as 50% pts have IgE levels within normal range

2.Specific IgE:

(i) Radio-allergosorbent test (RAST) (ii)Modified RAST

Stabilized allergen is incubated with patient’s serumany specific IgE binds to allergen identified by a second incubation with labelled anti-IgE.

Radio-allergosorbent test (RAST)

Indications:

1. When there is C/I to SPT

2. Where SPT unavailable

3. When SPT difficult to interpret

Disadvantages:

More expensive

Delayed(takes longer)

No more sensitive or specific to SPT

(III)Nasal allergen challenge (nasal provocation) test

Indication:

- +ve history & –ive SPT

• Subjective –symptom scores, VAS

• Objective –sneeze count, nasal inspiratory peak flow , rhinomanometry , acoustic rhinometry , spirometry,pulmonary peak flow

Disadvantages1.Time consuming 2.Difficult3.Excessive lab facilities4.Trained staff5.Resuscitation equipment

CT scan-Nose and PNSNasal endoscopy

Complications (Co-morbidities)

• Nasal symptoms -noted 80% of asthmatics

• Adults-Asthma present in 22.5% of adults with AR, Vs 7.2% in general population (Laynaert, 1999 )

• Children-Ratio of asthmatics with AR to asthmatics without AR is even higher (Wright et al.,1996)

• Effective treatment of allergic rhinitis reduces development of subsequent asthma (Ragab et al., 2006)

Differential diagnosis

1.Vasomotor rhinitis (Intrinsic rhinitis/NANIPER)

2.Sinonasal polyposis

3.Rhinitis medicamentosa

4.Hormonal rhinitis

(Pregnancy, Hypothyroidism, OCP use )

5.CSF leak

Take a moment to consider differential diagnosis

Management of allergic rhinitis

1. Environmental control measures (Avoidance of allergens)

2. Patient education

3. Nasal douching

4.Medical therapy

5.Immunotherapy

6.Surgery

(I) Avoidance of allergens

• Best treatment method

• Not always practical

• Indoor allergens: Removing allergen from the indoor

environment should be a primary strategy for the management

and treatment of allergic disease

• Outdoor allergens:

• Avoid irritants: smoke, dust, vehicular & other atmospheric pollutants,

• Physical factors – extreme changes in temperature can produce symptoms

like allergic rhinitis but are non-IgE mediated responses

• Avoid foods & drugs to which you are allergic

• Avoid occupational irritants or change profession

General advice

Avoidance of indoor allergens

Avoidance of animal allergen

• Remove pet animals (cats, dogs) from bedroom

• Wash the pet weekly

Measures to avoid house dust mite

• Mattress covers

• Covers for pillows & bedding

• Vacuuming

• Regulation of ventilation & humidity at home

• Liquid nitrogen

• Acaricides

• Protein denaturating agents- Tannic acid

• Avoid walking in open grassy spaces

during hot, dry days

• Keep windows closed

• Wear facemask & sunglasses when

moving out

Pollen avoidance measures

(II) Patient education

Educate patients on environmental control measures,

which involve both the avoidance of known allergens

(substances to which the patient has IgE-mediated

hypersensitivity) & the avoidance of nonspecific, or

irritant, triggers

(III) Nasal douching

Neti Pot: Home remedy to clean nasal passages

•Saline irrigation

•Improves quality of life

(IV) Medical therapy

1.Antihistamines:

Topical: Azelastine

Systemic: Cetirizine, Levocetirizine,Fexofenadine, Loratadine, Desloratadine

2.Nasal Decongestants:

Topical: Oxymetazoline, Xylometazoline

Systemic: Phenylephrine, Pseudoephedrine

3.Mast cell stabilizers: Sodium cromoglycate nasal drop

4.Anticholinergics: Ipratropium bromide nasal spray

5.Corticosteroids:

Topical :Beclomethasone,Budesonide,Mometasone,Fluticasone

Systemic: Prednisolone

6.Leukotriene receptor antagonists: Montelukast, Zafirlukast

Steroid

• Most effective treatment for Allergic rhinitis(AR)

-Topical: Nasal spray or nasal drop

-Systemic:Oral, extremely effective

• Reduces inflammation & consequent hyperreacitvityreduce nasal symptoms, eye symptoms, improve smell sense

• Topical steroid when combined with antihistamines reduces risk of asthma exacerbation and hospitalization by 50% or more (Adams et al., 2002, Crystal peters et al., 2002)

• Fluticasone and mometasone have low systemic bioavailabilitylower risk

Antihistamines• Adverse effects of first generation antihistamines

“First-generation oral H1-antihistamines are not recommended when second-generation ones are available, due to safety concerns”

(Allergy. 2008 Apr;63 Suppl 86:8-160)

GA2LEN- Global Allergy and Asthma European Network

Allergy. 2010 Apr;65(4):459-66

Significance of wide therapeutic window (fexofenadine)

Low H1-antihistamine dose High

Ineffective Therapeutic Window Not tested for adverse effects

Maximum Studied dose

(Fexo 1380 mg)

Minimallyeffective dose(Fexo 60 mg)

Howarth PH. Advanced Studies in Medicine. 2004;4(7A):S508-512

Levocetirizine and desloratadine have some effects on nasal obstruction (Wilson AM, 2002)

• Topical vasoconstrictor: -imidazoline (eg, oxymetazoline)• systemic (oral) vasocontrictor -Phenylephrine - Pseudoephedrine.• Monotherapy with vasoconstrictors has limited role

• Oral decongestants + Antihistamineall cardinal symptoms of allergic rhinitis targeted

Decongestants

Mast cell stabilizer

• Sodium cromoglycate inhibits degranulation of sensitized mast cells

• 2% Nasal drop: Use 3 to 4 times daily limits compliance

• Poorly absorbed systemically excellent safety record

• Used before the onset of symptoms• Can be used in younger children < 2 years of age

Ipratropium Bromide

• Useful against nasal discharge

• Occasionally helpful in pts with AR who do not respond to topical steroid(Dockhorn et al., 1999)

Zafirlukast performed no better than placebo - seasonal alllergic rhinitis ( Pullerits T et al., 1999)

• Montelukast clinical efficacy seasonal Allergic rhinitis (Chervinsky P et al., 2004)

• Montelukast + loratadine -superior reducing day time nasal symptoms in seasonal Allergic rhinitis. (Meltzer EO et al., 2000)

• Montelukast + ebastine- better symptomatic control in allergic rhinitis.

• Montelukast -less effective than Intranasal steroid (Ratner PH et al., 2003)

• Leukotriene antagonist (Montelukast) doesn’t appear more effective than nonsedating antihistamines (Fexofenadine) (Wilson AM et al., 2004)

Antilukotrienes

(V) Immunotherapy

• Repeated administration of allergen extract induce state of immunological tolerance

• Render an allergy patient less symptomatic when exposed to the offending antigen

• Desensitization or Hyposensitization: because complete elimination of the allergic reaction is seldom achieved

• Subcutaneous injection or sublingual route

Contraindications

• Asthma(severe)

• Autoimmune diseases

• Beta-blockers or Anti-adrenergic medicines

• Children less than < 5 yrs

• Pregnancy (induction but not maintenance)

• Efficacy:

• Highly effective -selected patients (Grade A)

• Treatment for 3 to 4 yrs –improvement for 3 yrs following discontinuation (Durham SR et al.,1999)

• Children –seasonal rhinitis-ITX for 3 yrs-2 to 3 fold reduction –developing asthma (Moller et al.,2002)

• Offers long term disease modification & prophylaxis

Side effects of Immunotherapy

Local reactions - trivial

Systemic reactions-10%-up dosing phase

Occasionally – severe systemic reactions-general urticaria , severe asthma or anaphylaxis

(VI) Surgery

• Usually not indicated

• Not last resort but complementary

• Comorbid or complicating conditions eg Marked DNS, Turbinate hypertrophy, CRS

(VII) Complementary and integrative medicine(CIM) therapies

• Honey – For seasonal AR caused by pollen

• Chinese herbal medicine

• Acupuncture

Recent advances

(VIII) Human monoclonal antibody(Anti-IgE)

• Omalizumab - recent developments in the treatment of atopic diseases

first of several monoclonal antibodies (anti IgE antibody) Modulation of allergic inflammation expensive for routine treatment of AR primarily indicated -severe

asthma• Multiple randomized, double-blind, placebo-controlled studies -

efficacy in seasonal and perennial AR (Vignola AM et al.,2004)

Continued research on the molecular mechanism of allergic disease will inevitably generate new forms of therapy.

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