this presentation is on type 1 hypersensitivity, it gives you clear idea about how it is caused, what are the symptoms, and current treatments available. The ppt is short so that it do not confuse you with the topics. i can upload a still more clear ppt, if u guys are enjoying my skills, so do let me know about how my ppt helpd you.

1. What is hypersensitivity?
The ability of the immune system to respond inappropriately
to antigenic challenge.
 Types :
Hypersensitivity
Immediate Delayed type hypersensitivity
Type I Type IV
Type II
Type III

2. TYPE I HYPERSENSITIVITY
IgE mediated
Immediate
Most allergic reactions are IgE meditated
Allergy : reactions from other molecule from outside the
body to which most people don’t react to.
Allergens/Antigens:

3. Genetic predisposition : over reaction to unknown molecules or
allergens.
AntigenTh
cells
Hypersensitive
Sensitization
phase
First exposure
Subsequent
exposure

4. Sensitization phase
Antigens(pollens)
APC Lymph node
APC
Co-stimulatory molecule
Before exposure to antigen
TH cells – Naïve TH cells

5. Primed TH cell
TH2
cells
IL4
IL5
IL10
IL4
B
cells
IgMIgE
IL5
Eosino
phills
Degranulation, thus
effecting invading cells
and near by cells
Mast
cells
Affinity
Fc receptors IgE
IgE

6. Mast
cells
IgE
IgE
IgE
IgE
Sensitized mast cell
Subsequent exposure
Crosslinkag of antibodies
Degranulation
Pro inflammatory mediators
Histamine –smooth muscle
contractio , blood vessel dilation
Early phase reaction
Late phase reaction
Mild symptoms – hives, ecazema, asthama etc
High load of allergens - sever symptoms like increase in vascular permeability,
smooth muscle contraction, and thus cant supply enough oxygen to vital
organs leading to Anaphylaxis.
REFERENCES
Owen, J. A., Punt, J., & Stranford, S. A. (2013). Kuby immunology (p.
692). New York: WH Freeman.
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