Presentation on "Allergy" | Jindal chest clinic

This presentation gives an overview on "Allergy" including : Anaphylactic materials, Mechanism of Allergy, Immune Reaction, Sensitization, Analphylaxis, Diagnosis of Allergy, Treatment of Allergy, Treatment of Anaphylaxis, Prevention of Anaphylaxis, Diagnosis of Anaphylaxis, Antihistaminic agents, etc. For more information, please contact us: 9779030507.

1. ALLERGY

2. ALLERGY
“Analteredresponse(differentfromthenormallyseen)toanoffending
agent”
Atopy
Hypersensitivity

3. Manifestations
Rhinitis
Asthma
Urticaria
Eczematous(atopicdermatitis)
Anaphylaxis
(Aloneorcombinations)
Systemicmastocytosis

4. Anaphylactic materials
1.Heterologousproteins:
Hormones(Ins,VP,PTH)
Enzymes(Tryp,CT,Pnc,SK)
Pollenextracts
Non-pollenextracts
Foods(milk,eggs,seafood)
Antisera
Occupationrelatedproteins
Hymenopetravenom

5. 2.Polysaccharides
 Dextran
 Thiomerosal(vaccinepreservative)
3.Drugs:Protamine
 Antibiotics
 Localanaesthetics
 Musclerelaxants
 Vitamins
 Diagnosticagents
4.Occupationrelatedchemicals
Ethyleneoxide

6. Mechanism of Allergy
1.Sensitization:Childhoodorearly
adolescence
2.Activationonre-exposure
Antigenspecific

7. Activation
Antigen exposure (re)

Sensitized key
effectorcells
(Mstcells, basophils)
 IgEfixation
Ag specific activation

Mediator release
Lipids: LTB
4 Secretorygranule Cytokines
LTC
4, PAF, (preformed) IL-3, IL-4, IL-5,
PGD
2 Hist, Proteoglycans, IL-6, GM-CSF, IL-1,
tryptase, chymase INFr, TNF 

8. Immune Reaction
1.Onset
2.Immunologic
al
3.Allergen
quantity
4.Clinical
features
Immediate
< Minutes
IgEdependent
Preformed mediators
Minute
Pruritis; rhinorrhoea
bronchospasm; wheal
and flare;
bronchorrhoea
Late
4-6 hours
Cellular;
cytokines
Greater
Nasal block;
skin erythema&
induration;
PFT (BHR)

9. Sensitization
Antigen exposure

Processing by Ag presenting cells

Presentation via their MHC to
T cell subsets

Recognition & response
IL-4: T
H2 response IN Fr : T
H1 type

Activation of specific Allergen specific
B cells  Plasma cells  IgE

Sensitization of IgE
Fc
receptor bearing cells

10. Characteristics
Immediate/Late
Sudden/Episodic
Recurrent/Persistent
Spontaneousremissions/recurrences
Familial
Variable

11. ANAPHYLAXIS
Lifethreateningresponseofasensitizedperson,immediatelyafterspecific
antigenexposure.
Respiratorydistress
Vascularcollapse

12. Predisposing Factors
Immunogenexposure
Noproveninfluence:
-Age,sex,race
-Occupation,place
-Atopy(forPenicillin
therapyorinsectbites)

13. Diagnosis of Allergy
1.Circumstantial:Onset;antecedentadmn.
2.Specifichistorye.g.recurrence
3.Skintests
4.Specifictests:diseasedirected/others

14. Treatment of Allergy
General:Identifyingallergenicagents
Antihistaminics
Glucocorticoids:
Topical
Oral
Parenteral
Specific
Immunotherapy

15. Treatment of Anaphylaxis
Earlyrecognition
Epinephrine:
-S/C0.2–0.5mlof1:1000ml
Repeateddoses.
-Intothesite/tourniquet
-I.Vinfusion,2.5mlof1:10,000at
5to10min
Volumeexpanders:N.saline
Vasopressors:dopamine
Isoproterenol(1:200)0.5ml

16. Tmt. (contd.)
Oxygen,IntermittentPPB
Endotrach.Intubation/tracheostomy
Ancillaryagents
Antihistaminics–diphenyl–hydramine
(50-100mg)I/MorI/V
Aminophylline(0.25–0.5gm),I/V
Glucocorticoids:I/Vesp.forlaterrecurrence

17. Prevention of Anaphylaxis
1.Historyofpreviousepisodes
2.Crossreactivityofagents
3.Skintest:scratch/I.D.
Allergenicextracts
Penicillins/otheragents
4.Desensitization–slowvsrapid
5.Resuscitationfacilities

18. Protection against venom induced
anaphylaxis
Immunotherapy:Useofspecific/crossreactingvenom
Modificationofoutdooractivities;dressandhabits
Informationalbracelet
Epinephrinekit

19. Manifestations
Onset:withinseconds
Laryngealoedema:“Lump”,hoarseness,stridor
Bronchospasm
Cutaneouswheals,‘gianthives’
Schimitarsyndrome
Fatalcases:Angiooedema;(skin&upperrespir.tract,viscera)shock

20. Diagnosis of Anaphylaxis
Clinicalpicture
Prausnitz-Kustnerreaction:Passivetransferofcutaneoushypersensitivity
Passivesensitizationofahumanleukocytesuspension
RadioimmunoassayforspecificIgEantibodies
Elevationofbetatryptaselevelsi.e.mastcellactivation

21. Antihistaminic agents
1.H
1receptorantagonists:
 Chlorphenirmine
 Diphenylhydramine
 Astemizole,terfenatine
 Nonsedating;cetrizine,loratadine,fexofenadine
2.BothH
1andH
2agents:Doxepin
3.Others:Cyproheptadine,Hydroxyzine
Alphaadrenergicagents;Phenylepherine(Topical)
Mastcellstabilizers:Cromolyn

22. Systemic Mastocytosis
“Mastcellhyperplasia”
Indolent–cutaneous
features,vascularcollapse,
ulcerdis,hepatospleno,LN
Concomitanthaematologicaldis
Aggressive
Mastocyticleukaemia