Anaphylaxis is a serious allergic reaction that affects multiple body systems and can cause death. It is caused by an immune system response to an allergen that results in the release of chemicals like histamine from mast cells that cause symptoms. Symptoms can include skin issues, respiratory distress, gastrointestinal issues, and cardiovascular problems. Treatment involves epinephrine injection, antihistamines, corticosteroids, monitoring vitals, and emergency transport if needed. Prevention focuses on having emergency medications available and management plans for high risk individuals.

1. Anaphylaxis

2. Anaphylaxis
Anaphylaxis is a serious allergic reaction that is rapid in onset
and manifests as under and may cause death.
❖ Cutaneous : urticaria, angioedema, flushing
❖ Respiratory : bronchospasm, laryngeal edema
❖ Cardiovascular : hypotension, dysrhythmias,
myocardial ischemia
❖ Gastrointestinal: nausea, colicky abdominal pain,
vomiting, diarrhea
Mediated by biological substances
released from mast cells and basophils.
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3. Anaphylaxis - Etymology
❖ Ancient Greek
➢ aná - intensifier
➢ phúlaxis - protection (by antibodies)
Become extremely
sensitive to harmless
allergens to cause
anaphylaxis
Antibodies that normally
protect our body from
microbes
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Multi-systemic symptoms of Anaphylaxis
Allergen

5. Pathophysiology of Anaphylaxis
B Cell
Immediate hypersensitivity
reaction (minutes after
repeat exposure to
allergen)
Allergen(e.g. pollen)
Allergen
Exposure
IgE-secreting
B cell
IgE
B cell
Dendritic Cell
Production of IgE
TH2 Cell
Naive T Cell
Dendritic cell
IgE
Cytokines
Activation
of mast cell;
release of
mediators
Binding of IgE
to FCƐRI on
mast cells
Late phase reaction (2-
24 hours after repeat
exposure to allergen)
Vasoactive amines, lipid mediators
Binding of IgE
to FCƐRI on
mast cells
Mediators
B Cell
Activation of TH2
cells and IgE class
switching in B cell

6. ❖IgE-Dependent
❖Mechanism: IgE mediated reaction
➢ Allergens
■ Food : peanuts, dairy, meat, spices,fish
■ Medications : β-lactam antibiotics, ibuprofen
■ Biologic agents :
● monoclonal antibodies: infliximab, omalizumab
● allergens : challenge tests, specific immunotherapy
■ Natural rubber latex
■ Vaccines
■ Inhalants (rare) : horse or hamster dander, grass pollen
Anaphylaxis Immune Mechanisms &
Triggers
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7. ❖ Immunological mechnisms (IgE-Independent)
• Radio contrast media
• NSAIDs
• Dextrans(HMW Iron)
• Biological agents
❖ NonImmunological mechnisms (Direct mast cell activation)
• Physical factors- exercise, cold, heat, sunlight
• Ethanol
• Opiods
❖ Idiopathic Anaphylaxis
• Previously unrecognised allergen
• Mastocytosis/clonal mast cell disorder

8. Exercise induced anaphylaxis
(EIAn)
o Symptoms occur after physical activity.
o In one third of cases food, drugs (especially NSAID) &
change in temp, can be identified.
o When symptoms develop after food ingestion, the
condition is referred as food-dependent exercise induced
anaphylaxis (FDEIAn).
o Fasting before exercise is of utmost importance when no
precise food has been correlated with the clinical
manifestations.

9. Risk Factors for Anaphylaxis
❖ Concomitant Diseases
➢ Asthma, Allergic rhinitis and Eczema
➢ Mastocytosis
➢ Depression, cognitive dysfunction, substance misuse
❖ Drugs
➢ β-Adrenergic blockers; Angiotensin-converting enzyme (ACE) inhibitors
➢ Sedatives, antidepressants, narcotics, recreational drugs
➢ Alcohol may lower patient’s ability to recognize triggers and symptoms
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10. ❖ Cofactors that Amplify Anaphylaxis
➢ Exercise: may be food dependent or food independent;
➢ NSAIDs
➢ Acute infection
➢ Emotional stress
➢ Disruption of routine—for example, travel, jet lag
➢ Premenstrual status in women and girls

11. Anaphylactic preparedness
Algorithm Management of Anaphylaxis
1. Manpower(trained in prompt assessment and
management of anaphylaxis)
2. Equipments:- (oxygen, suction, larygoscope,
ambu bag, mask, endotracheal tube, IV canulas)
3. Drugs
4. Fluids
5. Communication

12. Initial management
Yes
• Assess airway, breathing,
circulation, mentation
• Inject epinephrine(IM)*
• Supine position
• IV access, oxygen, monitoring
No
Initial assessment supports
potential anaphylaxis?
Consider other diagnosis
*0.01ml/kg Epinephrine1:1000[IM]

13. Good clinical
response?
Yes
No
Recumbent position with elevation
lower extremity • Establish airway,
O2 • Repeat epinephrine injection if
indicated
• IV fluids1 if hypotensive
Consider inhaled bronchodilators2 if
wheezing
• H1 and H2 antihistamines3
• Corticosteroids4
• Observation
• Autoinjectible
epinephrine
1NS or RL-30 mL/kg in 1st hr
2 Nebulised Albuterol- (0.83 mg/mL [3 mL]) via mask with O2
3cetrizine-0.25 mg/kg up to 10 mg PO, Ranitidine-1 mg/kg up to 50 mg IV
4methylprednisolone- 1-2 mg/kg up to 125 mg IV

14. Poor clinical
response
• Epinephrine intravenous
infusion*
• Other intravenous
vasopressors
• Consider glucagon
Cardiopulmonary arrest during
anaphylaxis:
• CPR and ACLS measures • Consider:
High-dose epinephrine
Rapid volume expansion
Atropine for asystole or pulseless
electrical activity • Transport to
ICU
*0.01 mL/kg/dose of 1:10,000 IV

15. POSTEMERGENCY MANAGEMENT
Antihistamine-Cetirizine (5-10 mg qd) or
loratadine (5-10 mg qd) for 3 days
Corticosteroids(Optional): Oral prednisone (1 mg/kg up to 75
mg) daily for 3 days
Preventive treatment
• Prescription for epinephrine
autoinjector(Epipen) and antihistamine
• Written plan outlining patient emergency
management
• Follow-up evaluation to determine/confirm

16. • Thank You