Anaphylaxis is a severe, life-threatening allergic reaction that requires immediate treatment to prevent harm or death. Epinephrine injection is the first-line treatment and should be administered promptly if anaphylaxis criteria are met. Symptoms may involve multiple organ systems such as the skin, respiratory tract, gastrointestinal tract, and cardiovascular system. Precautions must be taken to monitor for potential biphasic reactions in the hours after the initial episode. Strict allergen avoidance and use of medical alert devices can help prevent future dangerous reactions.

1. ANAPHYLAXIS
BY DR MRIDUL MURALI KRISHNA
DNB FAMILY MEDICINE RESIDENT

2. Atopy
 The term ATOPY implies a tendency to manifest asthma, rhinitis, urticaria, and
atopic dermatitis alone or in combination, in association with the presence of
allergen-specific IgE.
 However, individuals without an atopic background may also develop
hypersensitivity reactions, particularly urticaria and anaphylaxis, associated with
the presence of IgE.

3. Risk Factors
 Mild Asthma: Relative Risk 2
 Severe Asthma: Relative Risk 3
 Known Food Allergy, Hymenoptera Sting allergy or medication allergy
 Risk factors for a poor outcome include
 Older age,
 Use of beta blockers
 Presence of preexisting asthma.
 Some individuals suffering from recurrent episodes of idiopathic anaphylaxis
possess morphologically aberrant mast cells in their bone marrow that express
a mutant, constitutively active form of c-kit, even without evidence of frank
mastocytosis

4. Precautions
 Anaphylaxis is a life threatening condition that requires
 Immediate ABC Management
 Epinephrine injection IM
 Biphasic reactions occur in up to 20% of cases
 Second acute anaphylactic reaction despite no repeat exposure to the original allergen
 May be delayed up to 8 hours later (24-72 hour delay has been reported in atypical
cases)

5. Causes
 Idiopathic
 Consider mastocytosis
 Hymenoptera Allergy (Bees, wasps, fire ants)
 Food Allergy (30% of anaphylactic episodes, especially in children under age 4 years)
 Cow's Milk
 Egg whites
 Fish
 Peanuts
 Tree nuts
 Sesame
 Food additives
 Shellfish

6. Causes (continued)
 Medications (most common in age over 55 years)
 Penicillin Allergy (75% of anaphylactic deaths)
 NSAIDs or Aspirin
 Radiographic Intravenous Contrast Material
 Allopurinol
 ACE Inhibitors
 Opioids
 Interferon
 Allergic Contact Dermatits
 Latex Allergy
 Misc – Animal Dander

7. Signs – Typical Presentation
 Urticaria and Angioedema (90% of cases)
 Respiratory distress
 Upper airway obstruction (70% of cases)
 Lower airway obstruction may occur, especially in Asthma
 Cardiovascular collapse with Hypotension (45% of cases)
 Gastrointestinal symptoms such as Vomiting (45% of cases)
 Neurologic symptoms such as Headache or Dizziness (15% of cases)

8. Signs - MILD
 General
 Feeling impending doom
 Pruritus (uncommon without rash)
 Metallic Taste in mouth
 Naso-ocular
 Itchy nose or eyes
 Sneezing
 Clear, watery Eye Discharge or Nasal discharge
 Skin (occurs)
 Urticaria: Hives
 Angioedema: Facial swelling and Lip swelling

9. Sign - MODERATE
 Neurologic
 Dizziness
 Weakness
 Gastrointestinal
 Nausea, Vomiting
 Bloody Diarrhea
 Abdominal Pain
 Fecal urgency or Incontinence
 Genitourinary
 Uterine cramps
 Urinary urgency or Incontinence

10. Signs – SEVERE (ANAPHYLAXIS)
 Airway Compromise
 Hoarseness or Dysphonia
 Stridor
 Inability to manage own secretions
 Airway posturing (sniffing position)
 Breathing Compromise
 Wheezing and bronchospasm
 Dyspnea
 Tachypnea
 Hypoxia
 Increased work of breathing

11. Signs – SEVERE (ANAPHYLAXIS)
 Circulatory compromise
 Hypotension
 Tachycardia
 Hypoperfusion
 Syncope

12. Labs: Confirms diagnosis
 Do not rely on labs to make or treat acute episode
 Serum histamine
 Requires special handling for accuracy
 Obtain first level within 1 hour of symptom onset
 Compare to baseline level
 Serum tryptase
 Levels rise 30 minutes after onset and peak at 1-2 hours
 Obtain level on presentation, in 1-2 hours and 24 hours after presentation

13. Diagnosis – If 1 of the Criteria met
 Criteria 1:
 Acute illness onset within minutes to hours AND
 Skin or mucosal effects (e.g. Hives, Pruritus, Flushing, swollen lips/Tongue/uvula)
AND
 Respiratory distress (e.g. Dyspnea, bronchospasm) or Cardiovascular collapse
(e.g. Hypotension, Syncope)

14. Diagnosis – If 1 of the Criteria met
 Criteria 2:
 Acute illness onset within minutes to hours after likely allergen exposure
AND atleast TWO of the following
 Skin or mucosal effects (e.g. Hives, Pruritus, Flushing, swollen lips/Tongue/uvula)
 Respiratory distress (e.g. Dyspnea, bronchospasm)
 Cardiovascular collapse (e.g. Hypotension, Syncope)
 Gastrointestinal symptoms persist (e.g. abdominal cramping, Vomiting)

15. Diagnosis – If 1 of the Criteria met
 Criteria 3:
 Hypotension within minutes to hours after likely allergen exposure
 Systolic Blood Pressure with 30% decrease from baseline or <90 mmHg (adults)
 SUMMARY
 Anaphylaxis is present if allergen exposure and Hypotension or two
compromised organ systems

16. GENERAL MEASURES
 1. ABC MANAGEMENT
 2. SUPPLEMENTAL OXYGEN

17. Anaphylaxis with Airway compromise
 Epinephrine is the mainstay of Anaphylaxis management and must not be
delayed
 Administer within 5 minutes of presentation
 Narrow window of opportunity with Epinephrine
 Prior to complete airway obstruction and cardiovascular collapse
 Vasoconstricts, bronchodilates and decreases airway edema
 Epinephrine IM is safe EVEN IN OLDER PATIENTS and should not be withheld
when Anaphylaxis criteria are met

18. Anaphylaxis with Airway compromise
 Epinephrine (1:1000 concentration = 1 mg/ml)
 Intramuscular dosing preferred over subcutaneous
 Due to more reliable and faster rise in blood levels
 Typically injected in lateral thigh
 Repeat every 5 to 15 minutes prn up to 3 doses
 Cardiac monitoring required for repeat dosing
 Epinephrine via vial
 Adult: 0.5 mg (0.5 ml) of 1:1000 Epinephrine IM
 Child: 0.01 mg/kg (0.01 ml/kg) IM up to 0.3 mg (0.3 ml)
 Epinephrine Autoinjector (preferred if available, as reduces errors and speeds delivery)
 Adult and children over 30 kg or 66 pounds: 0.3 mg autoinjector
 Children under 30 kg or 66 pounds: 0.15 autoinjector

20. Anaphylaxis with Airway compromise
 Anaphylaxis "Dirty" Epinephrine drip ("dirty epi drip")
o Indicated if repeat intramuscular Epinephrine dosing is required for Anaphylaxis
o Order at the time of second Epinephrine injection
o Preparation:
o Aim - Epinephrine 1 mcg/ml solution
o Draw up 1 mg of Epinephrine (1 ml of 1:1000 or 10 ml of 1:10000)
o Inject 1 mg Epinephrine into 1 Liter bag of Normal Saline (now 1 mcg/ml Epinephrine)
o Given 1 cc/20 drops AND 1 mcg/ml Epinephrine
o Goal rate: 6 mcg/min
o Equates to 2 drops per second

21. Anaphylaxis with Airway compromise
 Protocol 1: Hypotensive, unstable patient
 Draw into syringe, 10 ml (10 mcg) from 1 mcg/ml Epinephrine solution
prepared above
 Inject 5 ml (5 mcg) IV (may repeat second 5 ml/5 mcg dose)

22. Anaphylaxis with Airway compromise
 Protocol 2: Hypotensive, unstable patient
 Open Epinephrine solution IV (flows at 20-50 mcg/min through 18 gauge IV)
 Provider stands by the bedside and closely controls infusion
 Titrate until patient hemodynamically stable
 Decrease the Epinephrine flow as patient becomes hemodynamically stable
 Decrease flow towards 1-4 mcg/min
 Wean as approach cummulative max IV Epinephrine dose
 Max cummulative dose: 100 mcg (3-5 min with open IV)
 Equivalent of the initial Anaphylaxis guideline
 Recommended bolus of 0.1 mg IV push over 5 minutes

23. Anaphylaxis with Airway compromise
 Protocol 3: Cautious titration
 Start infusion at 1 mcg/min and titrate to effect (typically 1-4 mcg/min)

24. Anaphylaxis with Airway compromise
 Unresponsive to Epinephrine
 Glucagon 3.5 to 5 mg IV - if patient uses Beta-Blockers
 May repeat if no Blood Pressure response within 10 minutes
 Norepinephrine may also be considered

25. Hypotension
 Due to Vasodilitation and third spacing
 Fluid Resuscitation with isotonic saline (NS, LR)
 Adult: 2 Liters Normal Saline
 Child: 10-20 ml/kg per bolus until Hypotension improves
 Large volumes may be required
 Pressors (e.g. Norepinephrine, Dopamine) may be required
 Consider Epinephrine by continuous IV infusion

26. Respiratory Distress
 Nebulized Beta adrenergic agonist (e.g. Albuterol)
 Consider for signs of lower airway obstruction
 Consider Endotracheal Intubation

27. Urticaria, Pruritus or Flushing
 General: H1 Antagonists
 NOT a first-line agent in Anaphylaxis management
 Use ONLY as an ADJUNCT TO EPINEPHRINE and ABC Management
 Effects are delayed 1-2 hours from delivery
 Does not reverse upper airway obstruction or improve Hypotension
 Diphenhydramine (Benadryl)
 Chlorpheniramine Maleate
 1 mg/kg intramuscular or intravenous is indicated in children even if less than
1 year of age

28. Severe or persistent symptoms not
resolved in 30 min
 CORTICOSTEROIDS
 NOT A FIRST-LINE AGENT in Anaphylaxis management
 Use ONLY as an ADJUNCT TO EPINEPHRINE AND ABC MANAGEMENT
 Effects are delayed 6 hours from delivery
 Studies proving benefit are lacking
 Consider for prevention of biphasic reaction, protracted reaction or in comorbid Asthma with
Wheezing
 Hydrocortisone - 5 mg/kg IV
 Methylprednisolone every 6 hours
 Adult: - 60-125 mg IV/IM
 Child: - 0.5-1 mg/kg IV/IM
 Predisone 60 mg orally in adults (or Methyprednisolone 1-2 mg/kg orally in children)

29. Prevention
 Medical Alert Bracelet should be worn
 Strict avoidance of allergen
 Epinephrine Autoinjector, home injectable devices
 Keep one in place where most of time spent
 Bring an injector when traveling
 Consider Allergist referral
 Consider Skin Testing and Desensitization therapy
 Indicated if re-exposure is likely or unavoidable
 Clinic office administration of medications and injections
 Should include a policy to observe patient after injection for 20-30 minutes