1. Allergic Reactions & Anaphylaxis
Barry Barkinsky
EMS-I, Paramedic

2. Sections Path physiology Assessment findings in anaphylaxis Management
Basement findings in Allergic Reaction
Patient Education

3. https://www.youtube.com/watch?v=G9D- Vfmbt4s
overview
Vfmbt4s

4. Incidence In USA - 400 to 800 deaths/year
Parenterally administered penicillin accounts for 100 to 500 deaths per year
Hymenoptera stings account for 40 to 100 deaths per year
Risk factors: beta-blockers, adrenal insufficiency

5. Why do they die?

6. Causes of Deaths
Laryngeal edema and acute bronchospasm with respiratory failure account for >70%
Circulatory collapse accounts for 25%
Other <5% - ?brain ?MI

7. bronchospasm
Bronchospasm is a sudden constriction of the muscles in the walls of the bronchioles. It is caused by the release (degranulation) of substances from mast cells or basophils under the influence of anaphylatoxins.

8. Laryngeal edema
The acute laryngeal edema seen here that killed the patient was due to an anaphylactic reaction to penicillin. Such an allergy is a form of type I hypersensitivity reaction in which there is preformed IgE antibody on mast cells that quickly reacts with an antigen. The mast cells release histamine and other mediators that lead to the edema.

9. Allergic Reaction é Physiologic response to antigens
Oversensitive response = allergic
Occurs after sensitization to antigen
Antigen binds with Antibody
Less severe result in inflammatory response
Type I reaction involves antibodies attached to mast cells or basophils = most severe form

10. Define some terms
Antigen: any substance capable of inducing an immune response
Most antigens are proteins
Following exposure to an antigen the body releases antibodies

11. Define some terms Antibodies
Substances produced by B lymphocytes in response to the presence of a foreign antigen that will combine with and control or destroy the antigen, thus preventing infection

12. Define some terms Mast cells
Specialized cell of the immune system which contains chemicals that assist in the immune response
Systemic
mastocytosis

13. Define some terms Sensitized
The initial exposure to an antigen that results in an immune response

14. Allergic Reaction - definition
An exaggerated response by the immune system to a foreign substance

15. Allergic Reaction é Physiologic response to antigens
Oversensitive response = allergic
Occurs after sensitization to antigen
Antibody binds with Antigen
Less severe result in inflammatory response
Type I reaction involves antibodies attached to mast cells or basophils = most severe form

16. Primary response Initial response to an antigen – on 1st time exposure
several day response by immune system
Generalized antibodies IgG, IgM are released

17. Secondary response Specialized antibodies with memory now created
Specific to the antigen

18. The speed of the reaction is a good predictor of the severity of the reaction

19. Anaphylaxis
Systemic reaction of multiple organ systems to antigen-induced IgE-mediated immunulogic mediator release in previously sensitized individual

20. IgE mediated reactions
IgE-mediated hypersensitive reactions (allergic rhinitis, asthma,           atopic dermatitis)

21. Type 1 - immediate (or atopic, or anaphylactic)
Symptoms vary from mild irritation to sudden death from anaphylactic shock
Allergic asthma
Allergic conjunctivitis
Allergic rhinitis ("hay fever")
Anaphylaxis
Angioedema
Urticaria (hives)
Eosinophilia
Penicillin
Cephalosporin

22. Allergic Reaction Antigen Induces antibody formation Examples
Drugs (antibiotics)
Foods (nuts, shellfish)
Insect venoms
Animal serum
Incompatible blood types

23. Allergic reaction / Anaphylaxis
Antigens enter body by:
Injection
Ingestion
Inhalation
Absorption

24. Mast Cells and the Allergic Response

25. Mast Cells and the Allergic Response

26. Mitigating factors? Route of administration And???????????????
IMMUNITY

27. immunity

28. Pathophysiology- IMMUNITY
Immune Response
Exposure to antigen produces primary response with general antibodies
Immune system develops antigen-specific antibodies and memory – secondary response
Natural and acquired Immunity
Induced Active Immunity
Active and Passive Immunity

29. The immune system Natural immunity - OEM Acquired immunity
Naturally acquired immunity

30. Natural immunity Also called: innate immunity
Genetically predetermined
Not related to previous exposures
Everyone has “some” natural immunities

31. Naturally Acquired immunity
Results from exposure to antigens
Is enhanced by continued exposures
Is believed to be lifelong in duration

32. Induced active immunity
Also called artificially acquired immunity
Designed to protect from a future exposure to an antigen
Achieved through vaccination
Provides relative protection
Creates antibodies

33. Induced passive immunity
Same as induced active immunity but includes injection of antibodies
Tetanus is an induced passive immunity example
Duration is largely unknown and is estimated. Sometimes can be titered

34. HOW LONG IS Induced immunity is good for?
Until its not

35. Anaphylaxis Path physiology
Antigen enters body (primary response)
Antibodies produced
Attach to surface of mast or basophil cells
Mast cells become sensitized

36. Anaphylaxis Path physiology behind the scenes
Mast cells
Specialized cell which contains chemicals that assist in the immune response
In all subcutaneous/submucosal tissues,
Including conjunctiva, upper/lower respiratory tracts, and gut
Basophils
white blood cell which participates in allergic response
Circulate in blood

37. Anaphylaxis Pathophysiology
Antigen reenters body (secondary response)
Attaches to antibodies on mast or basophil cells
Mast cell degranulates, releases
Histamine
Leukotrienes
Slow reacting substance of anaphylaxis (SRS-A)
Eosinophil chemotactic factor (ECF)

38. Histamine Product of mast cells and basophils that causes:
Vasodilatation
Capillary permeability - angioedema
Bronchoconstriction
Contraction of the gut

39. Histamine in detail
Three histamine receptor types: H1 H2 H3

40. Histamine Acts on H1 receptors to cause Smooth muscle contraction
Increased vascular permeability
Prostaglandin generation (mediators)

41. Histamine * Release of more histamine from mast cells and basophils
Acts on H2 receptors to cause
* Increased vascular permeability
Gastric acid secretion
Stimulation of suppressor lymphocytes
Decreased PMN enzyme release
* Release of more histamine from mast cells and basophils

42. Histamine Acts on H3 receptors to cause
Inhibition of central, peripheral nervous system neurotransmitter release
Inhibition of further histamine formation, release

43. Decreased peripheral vascular resistance CAUSES
Vasodilatation
Decreased peripheral vascular resistance CAUSES
Hypotension
Tachycardia
Peripheral Hypoperfusion

44. Increased Capillary Permeability
Tissue edema, urticaria (hives), itching
Laryngeal edema
Airway obstruction
Respiratory distress
Stridor
Angioedema
Fluid leakage from vascular space
Hypovolemic shock

45. Anaphylaxis Path physiology
Antigen reenters body (secondary response)
Attaches to antibodies on mast or basophil cells
Mast cell degranulates, releases
Histamine
Leukotrienes
Slow reacting substance of anaphylaxis (SRS-A)
Eosinophil chemotactic factor (ECF)

46. Leukotrienes
Potent bronchoconstrictors, é vascular permeability & possibly coronary vasoconstriction
Slower onset than histamine
Effects last longer than histamine

47. Anaphylaxis Path physiology
Antigen reenters body (secondary response)
Attaches to antibodies on mast or basophil cells
Mast cell degranulates, releases
Histamine
Leukotrienes
Slow reacting substance of anaphylaxis (SRS-A)
Eosinophil chemotactic factor (ECF)

48. SRS-A
Potent bronchoconstrictor and inflammatory agent released by mast cells; an important mediator of allergic bronchial asthma.

49. Anaphylaxis Path physiology
Antigen reenters body (secondary response)
Attaches to antibodies on mast or basophil cells
Mast cell degranulates, releases
Histamine
Leukotrienes
Slow reacting substance of anaphylaxis (SRS-A)
Eosinophil chemotactic factor (ECF)

50. ECF
Eosinophil chemotactic factor (ECF)
A substrate released from mast cells and basophils during anaphylaxis which attracts eosinophils . A tetrapeptide mediator of Immediate Hypersensitivity .

51. Eosinophil
One of the five different types of white blood cell (WBC) belonging to the subgroup of WBCs called Polymorphonuclear Leukocytes . Characterized by large red (i.e. eosinophilic) cytoplasmic granules.
Eosinophil function is incompletely understood. They are prominent at sites of allergic reactions and with parasitic larvae infections ( helminths ). Eosinophil secretory products inactivate many of the chemical mediators of inflammation and destroy cancer cells. This phenomenon is most obvious with mast cell-derived mediators. Mast cells produce a chemotactic factor for eosinophils.
Produced in the bone marrow, eosinophils then migrate to tissues throughout the body. When a foreign substance enters the body, lymphocytes and neutrophils release certain substances to attract eosinophils which release toxic substances to kill the invader.

52. In plain English
When a foreign substance enters the body, lymphocytes and neutrophils release certain substances to attract eosinophils which release toxic substances to kill the invader.

53. Urticaria

54. Angioedema Swelling in mouth or throat
Less often the sheer amount of swelling means that so much fluid has moved out of your blood circulation that your blood pressure drops dangerously

55. Angioedema

58. Smooth Muscle Spasm Bronchospasm GI Tract Spasm Bladder Spasm
Respiratory distress
“Tight Chest”
Wheezing
GI Tract Spasm
Nausea, vomiting
Cramping, diarrhea
Bladder Spasm
Urinary urgency
Urinary incontinence

59. Classification Mild allergic reaction Moderate allergic reaction
Severe allergic reaction (anaphylaxis)

60. Mild Allergic Reaction
Characteristics
Urticaria (hives), itchy
Erythema (redness)
Rhinitis
Conjunctivitis
Mild bronchoconstriction
Usually localized (look on abdomen, chest, back)
No SOB or hypotension/hypoperfusion
Often self-treated at home

61. Erythema

62. Pruritus

63. urticaria

64. wheals

65. Conjunctivitis

66. Moderate Allergic Reaction
Characteristics
Mild signs/symptoms with any of following:
Dyspnea, possibly with wheezes
Angioneurotic edema
Systemic, not localized
No hypotension/hypoperfusion

67. Severe Allergic Reaction (Anaphylaxis)
Characteristics
Mild and/or moderate signs/symptoms plus
Shock / hypoperfusion

68. Clinical Manifestation
Dependent on:
Degree of hypersensitivity
Quantity, route, rate of antigen exposure
Pattern of mediator release
Target organ sensitivity and responsiveness

69. Assessment findings in anaphylaxis
Focused History and Physical Exam
Focused History
Sample and OPQRST history
Rapid onset usually seconds following exposure
Speed of reaction is indicative of severity
Previous allergies and reactions

70. Assessment findings in anaphylaxis
Physical Exam
Presence of severe respiratory difficulty / hypotension is key to differentiating anaphylaxis from allergic reaction

71. Clinical Manifestation
Severity varies from mild to fatal
Most reactions are respiratory, dermatologic
Less severe early findings may progress to life- threatening over a short time
Initial signs/symptoms do NOT necessarily correlate with severity, progression, duration of response
Generally, quicker symptoms = more severe reactions

72. Clinical Manifestation
First manifestations involve skin
Warmth and tingling of the face, mouth, upper chest, palms and/or soles, or site of exposure
Erythema
Pruritus is universal feature, erythema
May be accompanied by generalized flushing, urticaria, nonpruritic angioedema

73. Erythema
Erythema exsudativum multiform majus presents with typical or atypical targets mainly localized on the limbs and hemorrhagic erosions of at least one mucosal site. The skin detachment is below 10% of the body surface area.

74. Clinical Manifestation
May progress to involvement of respiratory system
cough
chest tightness
dyspnea
wheezing
throat tightness
dysphagia
hoarseness

75. Clinical Manifestation
Other Signs and Symptoms
lightheadedness or syncope caused by hypotension or dysrhythmia
nasal congestion and sneezing
ocular itching and tearing
cramping abdominal pain with nausea,vomiting, or diarrhea
bowel or bladder incontinence
decreased level of consciousness

76. Clinical Manifestation
Physical Exam findings may include
urticaria, angioedema, rhinitis, conjunctivitis
tachypnea, tachycardia, hypotension
laryngeal stridor, hypersalivation, hoarseness, angioedema

77. Insect Sting Hypersensitivity
Hymenoptera - yellow jackets, honeybees, hornets, wasps, bumble bees
90%: Local hives, Pruritus
10%: Massive local reaction, including swelling beyond two joints of extremity
1%: Systemic reaction
10%: have worse reaction on second sting
28%: have recurrent systemic reaction

78. Management
Treatment depends upon severity of reaction and signs/symptoms of its presentation

79. Management Optimal management requires
High index of suspicion (suspect, treat within minutes)
Early diagnosis
Pharmaceutical intervention
Observation
Disposition

80. Management of Anaphylaxis
Scene safety
Consider the Possibility of Trauma
Protect the Airway
Use Airway Adjuncts with care
Intubate early in severe cases to prevent total occlusion of the airway
Be prepared to place a surgical airway

81. Management of Anaphylaxis
Support breathing
High flow oxygen or assisted ventilation if indicated
Establish IV access
Patient may be volume depleted due to “third spacing” of fluid
Administer crystalloid solution at appropriate rate. Place a second IV if indicated

82. Patient Self-Management
Benadryl 50 mg p.o.
At any sign of anaphylaxis, self-administer IM epinephrine (Epi-Pen®, Ana-Kit®)
If short of breath or wheezing, use aerosolized epinephrine (Primatene Mist, Medihaler-Epi)

83. Mild Allergic Reaction
Often self-treated at home
Diphenhydramine mg IV or deep IM
IV is acceptable FOR LAST RESORT – HEROIC MEASURES
If stinger present, flick it away with credit card or fingernail
May consider (if available and indicated):
cimetidine or ranitidine
prednisone
inhaled beta-agonists

84. Moderate Allergic Reaction
High flow oxygen
IV NS
Titrated to systolic BP 90 mm Hg
ECG monitor
Beta agonists
Nebulized albuterol, isoetharine, terbutaline
IM terbutaline or epinephrine 1:1000 or IV aminophylline if severe bronchoconstriction
Diphenhydramine mg IM or IV
Methylprednisolone 125 mg IV
Transport

85. Anaphylaxis Airway and Breathing Circulation
High concentration oxygen
Ventilations, ETT, alternative airway prn
Consider inhaled beta agonists
Circulation
Large bore IV NS X 2
Quickly titrate fluids to perfusion with bolus therapy
ECG monitor
Treat as pre-arrest patient

86. Anaphylaxis FOR FAILURE TO RESPOND TO PREVIOUS
Epinephrine mg 1:10,000 IV prn
Hypotension unresponsive to fluids and epinephrine è consider dopamine ~10 mcg/kg/min
Bronconstriction unresponsive to Epi è consider aminophylline
Diphenhydramine 50 mg IV
Methylprednisolone 125 mg IV
Rapid transport

87. Disposition
Regardless of response to therapy, all patients with systemic features must be observed for 6 to 8 hours

88. Latex Allergies
Due to a growing number of persons experiencing latex allergies, EMS providers should be prepared to treat patients with such allergies
Have latex free equipment
Use the patient’s latex free supplies

89. QUESTIONS?

90. What specific information would you like at this point?
Case Presentation #1
You are dispatched to an electronics manufacturing plant to see a 28-year-old woman. The woman believes she is having an allergic reaction. Security officers will meet you at the front gate and escort you to the patient.
What specific information would you like at this point?

91. Case Presentation #1
You find this patient in an office area sitting at her desk. From a distance, you notice she is awake and speaking clearly. She does not appear to have any breathing difficulty. She states she had just returned from lunch and began to feel hot and light headed. Her friend pointed out that the patient’s arms and neck are very red, and that her face appears “puffy”.

92. Case Presentation #1
The patient states she is allergic to peanuts but has not eaten any. She went to a health food café where she had grilled chicken and steamed vegetables. She has no other past history and takes no medications. Her last allergic rx was similar to this. Vitals are: BP-116/70; Pulse-100; RR-20; Lung sounds-clear and equal. No difficulty swallowing, redness to her arms, chest, neck and face.
Would you like to perform any other procedures/exams/testing or obtain other history before treating?

93. So, what is your complete treatment plan for this patient?
Case Presentation #1
So, what is your complete treatment plan for this patient?

94. Case Presentation #2
39 year-old male found at home in respiratory arrest with a bradycardic carotid pulse. His wife states he was helping a friend paint when he was apparently stung by a bee. He walked into the house, saying “I don’t feel good,” and collapsed.

95. Case Presentation #2 PMH: depression, gastritis, seasonal allergies
Medications: Ritalin, Zantac, Prozac, Claritin
No known drug allergies
No prior reactions to hymenoptera
What therapies would you like to begin for this man?

96. Case Presentation #2 You have done the following:
intubated orotracheally
administered intravenous epinephrine, 0.5 mg & Diphenhydramine 50 mg
started 2 large-bore IVs of NS and given 500 cc fluid
At this point, the patient no longer has a pulse

97. Case Presentation #2 You begin CPR and give the following:
Dopamine drip at 10 mcg/kg/min
Epinephrine, 1:10,000, 1 mg IV q 3-5 min
You now note the following:
ECG: Idioventricular rhythm
Lung Sounds: difficult to hear
Obvious facial edema
Can you think of any ideas for further treatment?

98. How to avoid future stings
1. Don’t “smell like a rose” - avoid scented soaps and fragrances
2. Wear garments that fit close to the body. Insects can become trapped in loose-fitting clothing and will sting defensively.
3. Wear shoes outdoors at all times, in addition to long pants and long-sleeved shirts.

99. How to avoid future stings
4. Wear clothing in colors not attractive to bees: white, red, grey. Avoid floral designs and brown clothing, which may mimic the color of the bee’s natural predator, the brown bear.
5. Wasp or hornet nests or beehives near the home should be destroyed by a professional exterminator.

100. How to avoid future stings
6. Stay away from insect feeding grounds: flower beds, fields of clover, garbage, orchards with ripe fruit.
7. Avoid outdoor picnics.