ALLERGIC RHINITIS

Syam chandran C

Definition

• A Symptomatic disorder of nose induced by an IgE mediated inflammation after allergen exposure.

• Associated with episodic attacks of sneezing, watery Rhinorhoea and watering of the eyes.

• May also present with tightness of chest due to sub clinical bronchospasm.

Etiology

• Allergic rhinitis is the commonest chronic disease. Its causation is multi factorial. Manifestation is multifocal.

• The symptoms of patients and type of allergy depends on a number of factors.

• Allergens are the causal substance of AR. They are capable for producing the body produce IgE antibodies.

• Factors may be classified as :

–Precipitating factors–Predisposing factors

Precipitating factors

• Aerobiological flora : This is determined by the allergens present in that environment of which inhalant allergen is more common.

• Nasal physiology : Altered nasal cycle

Predisposing factors

• Hereditary : Multiple gene interactions are responsible for allergic phenotype. Genes of chromosomes 5,6,11,12,14 seem to control inflammatory process in atopy. A family history of similar or allied complaints is common.

• Endocrine : Pubertal , marital, natal and menopausal conditions have the potential to influence the nose significantly.

• Psychological

• Focal Sensitivity

• Physical : Changes in humidity, temp and pollution of air can contribute to the development of allergic rhinitis. Living conditions like residential and workplace conditions also play an act.

• Infections

• Age and Sex

• Industrialization and urbanization

• IgA Deficiency

Common allergens

• Pollens : amaranthus, cassia, prosopis, ricinus, albizia, panthenium, artemisia

• Molds : the commonest fungal spores in India are cladosporium, pencillium, trichoderma etc

• Insects : bed bugs, cockroach, house flies, mosquito, fleas etc• Animals : pets like cat and dog. Also from horse, rabbits,

guinea pigs, monkeys, mice.• Dust mites : dermatophagoides can sensitize people.• Ingestants : eggs, strawberries, nuts, fish. Citrus fruits and

nuts also seems common allergens.

Classifacation

• Seasonal

• Perennial

Seasonal

• Hay fever or summer cold.

• Stiffy/runny nose.• Paroxysm of sneezing• Itchy nose/eyes/throat.• Excess mucus in nose/

throat

Hay fever – It is a misnomer because neither it is caused by hay nor it produces fever

Summer Cold – Should not be confused with acute rhinitis that is caused by virus and not by allergens

Rose fever – It is also a misnomer because colorful or fragrant flowering plants rarely cause allergy as there pollens are too heavy to be airborne

Perennial A R

• Caused by allergens that are present throughout the year include animal dander, cosmetics molds, food and other pets.

Clinical features

• Diagnostic symptoms including the following :• Nasal pruritus • Paroxysms of sneezing• Rhinorrhea

• Pale bluish edematous nasal mucosa.

• Bulky edematous turbinates with bluish / purple tinge of the mucosa

• Mucosa coated with clear/ mucoid secretions• In advance stage – polyp may be formed• Thickening of the nasal septum

Classical signs :• Overriding maxillary incisors• High arched palate• Allergic shiners• Allergic salute• transverse crease above the tip of nose and lower eye

lid • Conjunctival congestion• Peri-orbital swelling

Investigations

• Total WBC and DC• AEC• Histamine test• Nasal Smear• Intranasal provocation test

Specific tests (in vivo tests)

Skin test :

Sub Cuticular test or (prick/scratch test)• More accurate and lower incidence of

false positive results.• Contra indicated in case of

dermographism, anti histaminic, anti- inflammatory or decongestant treatment.

Intra dermal skin test :• Higher chance of anaphylaxis and has to

be done only with resuscitation equipment ready

Skin end point titration test• Quantitative intradermal test for specific

allergen

Other tests

Nasal challenge (nasal provocation test)

Nasal cytology• Using dry wipe technique without surface

anesthesia• Following cell types are noted :• Eosinophil• Mast cells• Epithelial cells • Lymphocytes• Neutrophils• Goblet cells

In vitro tests

• RAST (Radio-allergo-sorbant-test)

• FAST (Fluro-allergo-sorbant-test)

• PRIST (Paper immuno-allergo-sorbant test)

Other tests

• X ray PNS

• CT OMC

• Nasal endoscopy

Treatment

Medical

• Avoidance of Allergen

• Pharmaco therapy

a) Anti histaminic drugs like loratidine, rupatidine, levocetrizine etc…

b) Steroids like fluticasone, momentasone, beclomethasone, budesonide etc…

c) Sodium chromoglycate stabilizes the mast cells and prevents its degranulation

d) Decongestants pseudoephedrine hydrochloride, phenylephidrine hydrochloride etc…

e) Saline irrigation of the nasal cavities

• Immuno therapy

• In case where the above methods got failed and in severe AR.

• Helps in reducing the specific serum IgE level and a decrese in basophil sensitivity and increase IgG blocking antibody level which help in preventing the allergen from reaching the mast cells and thus preventing there degranulation.

• Surgical– Limited to reduction of the size of the

turbinates , correction of septal deviation and limited endoscopic sinus surgery if sinus are involved.

– Cauterisation– Septoplasty– Inferior turbinectomy– Laser and cryosurgery

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