Chapter 27
Immunology
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27-1
Objectives
27-2
Causes of Allergic Reactions
27-3
Allergic Reaction
• An exaggerated
response by the
body’s immune system
to a substance
27-4
Allergic Reaction
• The substance that causes an allergic
reaction can enter the body in four
ways:
1.
2.
3.
4.
Ingestion
Injection
Inhalation
Surface absorption
27-5
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•
•
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Causes of Allergic Reactions
Ingestion
Aspirin
• Berries
Nonsteroidal anti- • Eggs
inflammatory
• Seafood
drugs
• Chocolate
Insulin
• Grains
Antibiotics
• Beans
Peanuts
• Food
Tree nuts
preservatives
Milk products
(sulfites)
27-6
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•
•
•
•
•
•
•
•
Causes of Allergic Reactions
Injection
Bees
• Antivenin
Wasps
• Dyes used in
diagnostic X-rays
Yellow jackets
and
scans
Hornets
•
Animal
serum
Spiders
(vaccines)
Fire ants
• Transfusion of
Scorpion
blood or blood
Jellyfish
products
Snakes
27-7
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•
•
•
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Causes of Allergic Reactions
Inhalation
Pollen
• Paint
Mold
• Perfume
Dust
• Animal dander
Grasses
• Bug spray
Mildew
• Latex
27-8
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•
•
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Causes of Allergic Reactions
Surface Absorption
Pollen
Latex
Soap
Cleansers
Fertilizer
Poison ivy, oak, sumac
27-9
Latex Allergy
• Latex
– Contains proteins that
may be absorbed
through the skin or
inhaled
– Can cause an allergic
reaction in
susceptible persons
27-10
What Happens in an Allergic Reaction?
27-11
Antigen
• Any substance that is foreign to an
individual and causes antibody
production
27-12
Antibody
• A substance
produced by white
blood cells to defend
the body against
bacteria, viruses, or
other antigens
27-13
Sensitization
• The formation of antigen-specific
antibodies
• Occurs with the body’s first exposure to
the antigen
27-14
Allergens
• An antigen that causes signs and
symptoms of an allergic reaction
27-15
Inflammatory Response
• Histamine release
– Increased blood flow to injured area
• Local arterioles and capillaries dilate
– White blood cells move to area of injury
– Capillaries lead plasma into tissues
– Swelling may be limited to one area of the
body (localized) or affect multiple body
systems (systemic)
27-16
Allergic Reaction
• Usually happens soon
after re-exposure to an
allergen
• Some reactions are mild
– Symptoms are not lifethreatening
• Anaphylaxis
– Severe allergic reaction
– Life-threatening emergency
27-17
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•
•
•
Signs and Symptoms
Respiratory
Tightness in the
• Noisy breathing
throat (“lump in
• Hoarseness
the throat”) or
• Stridor
chest
• Difficulty talking
Coughing
• Wheezing
Rapid breathing
Labored
breathing
27-18
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•
•
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Signs and Symptoms
Cardiovascular
Lightheadedness, fainting
Weakness
Increased heart rate
Irregular heart rhythm
Decreased blood pressure
Circulatory collapse
27-19
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Signs and Symptoms
Nervous
Restlessness
Fear, panic, or a feeling of impending
doom
Headache
Altered mental status, unresponsiveness
Seizures
27-20
Signs and Symptoms
Skin
• Warm, tingling feeling in
the face, mouth, chest,
feet, and hands
• Itching (pruritis)
• Rash
• Hives (urticaria)
• Red skin (flushing)
• Swelling of the face, neck,
hands, feet and/or tongue
27-21
Signs and Symptoms
Gastrointestinal
•
•
•
•
Nausea
Vomiting
Abdominal cramps, pain
Diarrhea
27-22
Signs and Symptoms
General
• Itchy, watery eyes
• Runny nose
27-23
Patient Assessment
27-24
Patient Assessment
• Scene size-up
• Primary survey
27-25
Priority Patients
• Patients who give a poor general
impression
• Patients experiencing difficulty
breathing
• Patients with signs and symptoms of
shock
• Unresponsive patients with no gag
reflex or cough
• Responsive patients who are unable to
follow commands
27-26
Secondary Survey
• SAMPLE history
• Vital signs
• Physical exam
– Focused exam if responsive
– Rapid medical assessment if unresponsive
27-27
Medical Identification
27-28
Anaphylaxis Kit
27-29
Latex Allergy
• If the patient has a latex allergy:
– Write “LATEX ALLERGY” clearly on your
report
– Include latex in allergy section of form
• Use latex-free supplies from latex-free
kit
• Communicate patient’s latex allergy
when transferring patient care
27-30
Emergency Care
27-31
Emergency Care
• Allergic reaction without signs of
respiratory distress or shock:
– Maintain an open airway
– Give oxygen
– Transport
• Reassess as often as indicated en route
27-32
Emergency Care
• If the patient has respiratory distress or
shows signs and symptoms of shock:
– Establish and maintain an open airway
– Give oxygen
– Obtain an order to give (or assist the
patient in giving) epinephrine
• Reassess patient in 2 minutes
• Record findings and prepare for transport
– Reassess every 5 minutes
– Transport promptly
27-33
Emergency Care
• If the patient’s condition improves:
– Supportive care
• If the patient’s condition worsens:
– Contact medical direction
– Treat for shock
– Be prepared to begin CPR and use AED
27-34
Questions?
27-35