Allergic Rhinitis Etiology Clinical features and Management

A study on Allergic Rhinitis

1. Allergic rhinitis

2. It is an IgE mediated immunologic response of nasal mucosa to airborne allergens It is characterized by watery nasal discharge,nasal obstruction, sneezing and itching

3. Aetiology Inhalent allergens Pollen grains,moulds,dust mite,insect parts,fibres and animal danders Genetic predisposition it plays an important part Chances of children developing allergy are 20% and 47%,if one or both parents are suffered from allergic diathesis

4. Pathogenesis IgE mediated type 1 hypersensitivity reaction to antigen(allergens) in a genetically susceptible person Type 1 Hypersensitivity causes local vasodilation and increased permeability Allergic response occurs in two pphases Acute or early phase leads to sneezing,rhinorrhea nasal blockage or bronchospasm Late or delayed phase due to inflammatory infiltrates it causes swelling, congestion and thick secretion

5. Clinical features The cardinal symptomsof seasonal nasal allergy include 1) paroxysomal sneezing(10-20)sneezes at a time 2)nasal obstruction 3) watery nasal discharge and itching The duration and severity of the symptoms may vary with the season

6. Symptoms of perennial allergy are not so severe as that of the seasonal type It include frequent colds,loss of sense of smell, postnatal drip, chronic cough and hearing impairment

7. Signs Nasal signs It includes nasal crease– a black line across the middle of dorsum of nose due to constant upward rubbing of nose Turbinates are swollen,thin watery or mucoid discharge is usually present

8. 2) Ocular signs . it includes oedema of lids,congestion and cobblestone appearance of conjunctiva, and dark circle under the eyes 3) Otologic signs It includes retracted tymphanic membrane or serous ottitis media as a result of eustachian tube blockage

9. 3)Pharyngeal signs . It includes granular pharyngitis due to hyperplasia of submucosal lymphoid tissue In children’s leads to mouth breathing 4)Laryngeal signs It include hoaseness and oedema of the vocal cords

10. Classification Duration of disease . Intermittent :symptoms are present less than 4 days a week or for less than 4 weeks Persistent :more than 4days a week or for more than 4 weeks

11. Severity of disease Mild: none of the following symptoms are present 1 ) sleep disturbances . 2) impairment of daily activities,leisure . 3) impairment of school or work . 4) troublesome symptoms Moderate to severe . One or more of the above symptoms are present

12. Investigation Total and differential count Nasal smear :it shows large number of eosinophils in allergic rhinnitis Skin prick test : excellent method to demonstrate the allergens and positive reaction is manifested by the formation of a central wheal and surrounding zone of erythema within 10-15 min

13. 4) Specific IgE measurements Radioallergosorbent test: it is an in vitro test and measures specific IgE antibody concentration in the patient serum 5) Nasal provocation test . In this small amount of allergens placed at the end of a toothpick and asking the patient to sniff into each nostril and to observe if allergic symptoms are produced

14. Complications It includes 1) Recurrent sinusitis 2) formation of nasal polyp in about 2% 3)serous ottitis media 4) orthodontic problem 5) bronchial asthma

15. Treatment Treatment can be divided into 1) Avoidance of allergens 2) Treatment with drugs 3)immunotherapy Drugs include ,nasal decongestants, corticosteroid,antichollinergics Sodium cromoglycate : It stabilizes the mast cells and prevent them from degranulation despite the formation of IgE – antigen complex

16. Leukotriene receptor antagonist includes Montelukast,pranlukast,and zafirlukast 3) Immunotherapy It is used when pharmacotherapy is failed it suppress the formation of IgG it also raises the titre of specific IgG . Subcutaneous immunotherapy is often used but now sublingual and nasal routes are also being employed