The document discusses anaphylaxis, a severe hypersensitivity reaction affecting multiple body systems, detailing its definitions, causes, pathophysiology, symptoms, diagnosis, and treatment methods. It emphasizes the role of allergens such as food, drugs, and insect stings, and outlines the critical need for immediate intervention, primarily using epinephrine. Additionally, prevention strategies, such as avoiding allergens and maintaining an adrenaline kit, are highlighted.

1. ANAPHYLAXIS
Fatima Al-Awadh

2. Objectives
 Define Hypersensitivity Reaction.
 Mention the Types of Hypersensitivity
Reactions.
 Define Anaphylaxis.
 Mention the Etiologic Causes.
 Explain the Pathophysiologic Mechanism.
 Mention the Signs & Symptoms.
 Demonstrate the Diagnostic Investigations.
 Display the Treatment & First Aid.

3. Hypersensitivity Reaction
 Injurious, or pathologic, immune reactions are
called hypersensitivity reactions.
 Hypersensitivity reactions may occur in two
situations.
 First, responses to foreign antigens may be
dysregulated or uncontrolled, resulting in
tissue injury.
 Second, the immune responses may be
directed against self antigens, as a result of
the failure of self-tolerance (autoimmunity).

4. Types of hyper sensitivity
reactions
Immediate Antibody- immune complex T cell-mediated
hypersensitivity mediated diseases diseases
Mast cell Antibodies Antibody- Reactions
release directed antigen of T
histamine against cell or complex lymphocytes
and other tissue deposit in
mediators antigens blood vessels

5. Anaphylaxis
 Ana (without), phylaxis (protection).
 Acute multi-systemic allergic reaction involving
the skin, airway, vascular system, and GI.
 Sever immediate (type I) hypersensitivity
reaction.
 True & pseudo-anaphylaxis.

6. Etiology
Causes of anaphylaxis in a study of 266 patients (Data
from Kemp et al)
2% Food
7%
Idiopathic
20% 34% Drugs
Exercise
37%
Latex, hormons, ins
ect bites

7. Etiology
Pharmlogic agents
• Antibiotics (penicillin)
• Nonsteroidal anti-inflammatory drugs (Asprin)
• intravenous (IV) contrast agents
Stinging insects
• Ants, bees, hornets, wasps, and yellow jackets.
Food
• Peanuts, seafood, and wheat
Latex
• Rare
• No latex-associated deaths

8. Pathophysiology
 First exposure
 Activation of TH2 cell → Stimulate IgE switiching
Allergen
B Cell
TH2 Cell

9. Pathophysiology
 First exposure
 IgE production
IgE secreting B cell
IgE

10. Pathophysiology
 First exposure
 IgE bind to mast cell
Mast cell
FcɛRI
IgE

11. Pathophysiology
 Second exposure
Allergen
 Recognition
Mast cell
FcɛRI
IgE

12. Pathophysiology
 Second exposure
 Activation of mast cell to release histamine
and other mediators Allergen
Mast cell
Mediators FcɛRI
IgE

13. Pathophysiology
Mediators
Vascoactive aminase &
Cytokines
lipid
Immediate
Late phase reaction (6-
hypersensitivity reaction
24 hours)
(minutes)

14. Signs & Symptoms
Skin
Itching flushing
hives (urticaria) swelling

15. Signs & Symptoms
Eyes
Itching tearing
swelling around the
redness
eyes

16. Signs & Symptoms
Nose &
mouth
Sneezing
runny nose nasal congestion
swelling of the
metallic taste
tongue

17. Signs & Symptoms
Lungs and
throat
wheezing or other
Difficulty breathing coughing chest tightness
sounds
increased mucus throat swelling or or a sensation of
change in voice
production itching choking

18. Signs & Symptoms
Heart and circulation
Dizziness weakness fainting
rapid, slow, or
low blood pressure
irregular heart rate

19. Signs & Symptoms
Digestive system
Nausea vomiting
cramps diarrhea

20. Signs & symptoms
Nervous system
Anxiety confusion
sense of impending
doom

21. Diagnosis
 The diagnosis of anaphylaxis is based upon symptoms
that occur suddenly after being exposed to a potential
trigger.
 Differential diagnosis
 severe asthma attack
 heart attack
 panic attack
 food poisoning
 An increased amount of tryptase protein can be
measured in a blood sample collected during the first
three hours after anaphylaxis symptoms have begun.
 tryptase levels are seldom elevated in food-induced

22. First Aid
Place patient in
Establish and
Trendelenburg
maintain airway.
position.
Give oxygen via Place a tourniquet
nasal cannula as above the reaction
needed. site.
Epinephrine at the
site of antigen Start IV to rise BP.
injection.

23. Treatment
 EPINEPHRINE
 Benadryl (diphenhydramine) - H1
antagonist
 Tagamet (cimetidine) - H2 antagonist
 Corticosteroid therapy
 In severe anaphylaxis, observe for 6 hours or
longer

24. Prevention
Avoid the responsible allergen (e.g.
food, drug, latex, etc.).
Keep an adrenaline kit (e.g. Epipen) and
Benadryl on hand at all times.
Wear medic Alert bracelets .
Venom immunotherapy is highly effective in
protecting insect-allergic individuals.

25. References
 Abbas & Lichtman, Basic Immunology 3E, Chapter 11
 http://www.authorstream.com/Presentation/Moiloa-898248-
anaphylaxis/
 http://med.mui.ac.ir/clinical/orjanc/Anaphylaxis.ppt
 http://www.uptodate.com/contents/anaphylaxis-symptoms-and-
diagnosis-beyond-the-basics
 http://www.oregonems.org/Downloads/Anaphylaxis.ppt

26. Thank You
Fatima Al-Awadh