Hypersensitivity disorders cld

Immune system Disorders
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M A R I A C A R M E L A L . D O M O C M A T, R N , M S N
INSTRUCTOR, CURA AND REHAB NRG II
SCHOOL OF NURSING
NORTHERN LUZON ADVENTIST COLLEGE

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Inflammatory and immunologic response
is normally helpful and protect against infection and can development
These responses also stimulates tissue growth and repair after injury
But if prolonged and excessive or occur at inappropriate time
Effect: normal cells, tissues or organs are damaged

Maria Carmela L.Domocmat, RN, MSN

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WHAT HAPPENS WHEN THE IMMUNE SYSTEM
DOESN’T WORK THE WAY IT SHOULD??


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Overreaction Underreaction
Hypersensitivity Immunodeficiency
Overreactions to invaders and Congenital
foreign antigens Acquired

Autoimmune response
When it fails to recognize self-
cells and attack normal body
tissues


Hypersensitivity Reaction or Allergic Reaction
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an immune malfunction whereby a person's body is hypersensitized to
react immunologically to typically non-immunogenic substances.


Definition of terms
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Atopy: the tendency to develop allergies for which
there is a genetic disposition and that involve
immunoglobulin E (IgE) antibody formation
AKA – atopic, allergic, hypersensitive
Allergy: describes the increased immune response
to the presence of an allergen (i.e., antigen)


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People must progress through two-step process to
become allergic
1) sensitization
2) reexposure to the allergen


General categories of hypersensitivity reactions
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Immediate
humoral or antigen-antibody
Delayed
cell-mediated


Types of Hypersensitivity
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IMMEDIATE

Type I: Immediate hypersensitivity
Type II: Cytotoxic hypersensitivity
Type III: Immune complex-mediated
hypersensitivity
DELAYED

Type IV: Delayed Hypersensitivity


Hypersensitivity
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There are four different types of hypersensitivities that result from
different responses of the immune system:
Type I: Immediate hypersensitivity
- onset within minutes of antigen challenge
- examples are allergies to molds, insect bites
Type II: Cytotoxic hypersensitivity
- onset within minutes or a few hours of antigen challenge
- examples are adult hemolytic anemia and drug allergies


Hypersensitivity
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There are four different types of hypersensitivities that result from
different responses of the immune system:

Type III: Immune complex-mediated hypersensitivity
- onset usually within 2-6 hours
- examples include serum sickness and systemic lupus
erythematosus
Type IV: Delayed Hypersensitivity
- inflammation by 2-6 hours; peaks by 24-48 hours
- examples include poison ivy and chronic asthma


ATOPIC ALLERGIES
Allergic rhinitis or hay fever
Urticaria or Hives
ALLERGIC ASTHMA
ANAPHYLAXIS
ALLERGY TO SPECIFIC ALLERGEN
Latex allergy
bee venom, peanut, iodine, shellfish, drugs

Type I:
Immediate hypersensitivity
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This is the type of hypersensitivity usually referred to as
“allergy”.


Type I:
Immediate hypersensitivity
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occurs when an IgE antibody response is mounted against
an antigen in the environment that is usually harmless
A single exposure to antigen isn’t enough to trigger
hypersensitivity, but the immune response may become
more severe with repeated exposure.


Type I hypersensitivity – sensitization to an inhaled allergen
or bee sting
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cytokines

→ →

Mast
cell

Antigens (red dots) from inhaled pollen are ingested and presented by
macrophages to T cells. Activated T cells produce cytokines leading to
the production of IgE, which binds to receptors on mast cells and causes
the release of histamine, which is responsible for allergy symptoms.
Onset is usually within minutes of contact with antigen.

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When the antigen enters through a respiratory mucosal
surface, it is taken up, processed and displayed by antigen-
presenting cells.
When the presented fragments “lock on” to helper T cell
receptors, the T cells become activated, secreting
cytokines.
The cytokines, in turn, stimulate IgE-producing B cells.
IgE binds to IgE-receptors on the surfaces of mast cells,
sensitizing them.


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histamine

Maria Carmela L.Domocmat, RN, MSN 20

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Allergens can be contacted in the ff ways
Inhaled
Ingested
Injected
contacted


Atopic allergy
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Inhaled Injected
Plant pollens Bee venom
Fungal spores Drugs
Animal dander Biologic subtances
House dust (ex: contrast dyes,
Grass Adenocotricotropic hormone)
Ragweed Contacted
Ingested Pollens
Foods Foods
Food additives Envt proteins
Drugs


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What are common allergenic foods?

Legumes (Peanuts and Soybeans)
Mollusks (snails, mussels, oysters, scallops, clams, squid)
Milk
Eggs
Fish (cod, salmon, haddock, etc.)
Crustacea (shrimp, crawfish, lobster. etc.)
Wheat
Tree nuts (almonds, walnuts, Brazil nuts, etc.)
Selected food additives

Atopic allergy
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MOST COMMON TYPE
INCLUDES :
Allergic rhinitis or hay fever
Urticaria or hay fever


Allergic Rhinitis
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AKA: HAY FEVER


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Allergic Rhinitis
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Triggered by reactions to airborne allergens
Types:
Seasonal: recur to same time of each of the year
Often coincide with timing of large environmental exposure
Chronic: or perennial rhinitis
Occur intermittently or continuous when exposed to allergen
Non-allergic rhinitis
Same manifestations are present
Although no allergic cause is identified immune system does not appear to
be involved


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Urticaria
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Urticaria may be acute (lasting less than 6 wk) or chronic
(lasting more than 6 wk).


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Many substances can trigger hives, including:
Animal dander (especially cats)
Insect bites
Medications
Pollen
Shellfish, fish, nuts, eggs, milk, and other foods

Hives may also develop as a result of:
Emotional stress
Extreme cold or sun exposure
Excessive perspiration
Illness (including lupus, other autoimmune diseases, and leukemia
Infections such as mononucleosis


Symptoms
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Itching
Swelling of the surface of the skin into red- or skin-colored
welts (called wheals) with clearly defined edges
The welts may get bigger, spread, and join together to form larger areas
of flat, raised skin.
They can also change shape, disappear, and reappear within minutes or
hours.
The welts tend to start suddenly and go away quickly. When you press
the center of a red welt, it turns white. This is called blanching.


Hives (urticaria) on the back and buttocks
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These are hives (urticaria) with the typical slightly-raised red
appearance, and are accompanied by itching. These are
located on the buttocks. Hives can be generalized over the
entire body or may be localized, and usually result from an
allergic reaction.

Hives (urticaria) - close-up
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Hives (urticaria) are raised,
red, itchy welts. The
majority of urticaria
develop as a result of
allergic reactions.
Occasionally, they may be
associated with
autoimmune diseases,
infections (parasitosis),
drugs, malignancy, or
other causes.

Hives (urticaria) on the chest
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Hives develop when histamine is
released into the small blood vessels
(capillaries). The capillaries dilate which
causes a welt, and fluid oozes into the
surrounding tissue, causing swelling.
Histamine also causes intense itching.


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Latex is a milky fluid that comes from the tropical rubber
tree,Hevea brasiliensis.
Hundreds of everyday products contain latex. Some
common ones are
Gloves
Condoms
Balloons
Rubber bands
Shoe soles
Pacifiers

Maria Carmela L.Domocmat, RN, MSN http://www.nlm.nih.gov/medlineplus/latexallergy.html

Latex exposure is associated with 3 clinical
syndromes
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first syndrome - irritant dermatitis.
It is a result of mechanical disruption of the skin due to the rubbing of gloves
and accounts for the majority of latex-induced local skin rashes. It is not
immune mediated, is not associated with allergic complications
second syndrome - delayed (type IV) hypersensitivity reaction
Result in a typical contact dermatitis.
Symptoms usually develop within 24-48 hours of cutaneous or mucous
membrane exposure to latex in a sensitized person.
Third syndrome - immediate (type I) hypersensitivity
most serious, and least common
mediated by an immunoglobulin E (IgE) response specific for latex proteins.
See http://emedicine.medscape.com/article/756632-overview#showall for more
information

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Maria Carmela L.Domocmat, RN, MSN http://www.mountnittany.org/assets/images/krames/7596.jpg

Allergic asthma
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See link: http://emedicine.medscape.com/article/137501-overview#showall for
additional information
Maria Carmela L.Domocmat, RN, MSN http://cureasthmaguide.com/wp-content/uploads/2010/02/inflammed-airways-complex.jpg

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Maria Carmela L.Domocmat, RN, MSN http://www.dentalgentlecare.com/images/lungs-asthma.gif

Clinical
Manifestations
of Immediate
Hypersensitivity
ASTHMA

Anaphylaxis
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Maria Carmela L.Domocmat, RN, MSN http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001847/bin/19320.jpg

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Nursing assessment
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H X : A C C U R A T E A N D D E TA I L E D H X
Describe onset and duration of problems
Ask abt work, school, home, environment, possible exposures
through hobbies, leisure time or sports activities
Ask presence of allergies among relatives
PHYSICAL ASSESSMENT


Clinical Manifestations of
Immediate Hypersensitivity

Allergy is characterized by a local or systemic
inflammatory response to allergens
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Local symptoms:
Nose: swelling of the nasal mucosa, rhinorrhea
Eyes: redness and itching of the conjunctiva (allergic
conjunctivitis)
Airways: bronchoconstriction, wheezing, sometimes
outright attacks of asthma
Ears: feeling of fullness, possibly pain, and impaired
hearing due to the lack of eustachian tube drainage.
Skin: various rashes, such as eczema, hives and contact
dermatitis.
Head: while not as common, headaches are seen in some
with environmental or chemical allergies.

Allergy is characterized by a local or systemic
inflammatory response to allergens
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Systemic allergic response
Is also called anaphylaxis
Depending of the rate of severity, it can cause cutaneous
reactions, bronchoconstriction, edema, hypotension, coma
and even death.


Hives Symptoms
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Itching
Swelling of the surface of the skin into red- or skin-colored
welts (called wheals) with clearly defined edges
The welts may get bigger, spread, and join together to form larger areas
of flat, raised skin.
They can also change shape, disappear, and reappear within minutes or
hours.
The welts tend to start suddenly and go away quickly. When you press
the center of a red welt, it turns white. This is called blanching.

http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001848/


Food allergies
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The body's immune system normally
reacts to the presence of toxins, bacteria
or viruses by producing a chemical
reaction to fight these invaders.
However, sometimes the immune
system reacts to ordinarily benign
substances such as food or pollen, to
which it has become sensitive. This
overreaction can cause symptoms from
the mild (hives) to the severe
(anaphylactic shock) upon subsequent
exposure to the substance. An actual
food allergy, as opposed to simple
intolerance due to the lack of digesting
enzymes, is indicated by the production
of antibodies to the food allergen, and
by the release of histamines and other
chemicals into the blood.

Food Allergy - Symptoms
Nausea
Diarrhea
Abdominal cramps
Pruritic rashes
Angioedema
Asthma/rhinitis
Vomiting
Hives
Laryngeal edema
Anaphylaxis

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Allergy tests
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SKIN TESTS
• Scratch or prick test
• Intradermal test
•O R A L F O O D C H A L L E N G E O R E L I M I N A T I O N D I E T
•L A B O R A T O R Y TESTS
CBC
Increased serum IgE
RAST (radioallergosorbent test)


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Skin Tests
Individual is inoculated with allergen by scraping or injection
Fast: results within 30’


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Prep
Discontinue Glucocorticoids and antihistamine 5 days b4 test (to avoid
suppressing allergic response during the test)
Nasal sprays to reduce mucous membrane swelling can be continued
but shld be discontinued if with antihistamine


Skin Tests: Intradermal or Scratch test
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• The allergens are either injected intradermally or into small
scratchings made into the patient's skin
• If the patient is allergic to the substance, then a visible inflammatory
reaction will usually occur within 30 minutes.
• This response will range from slight reddening of the skin to full-blown
hives in extremely sensitive patients.
• Problems: some people may display a delayed-type hypersensitivity
(DTH) reaction which can occur as far as 6 hours after application of
the allergen and last up to 24 hours. This can also cause serious long-
lasting tissue damage to the affected area. These types of serious
reactions are quite rare.


http://www.allergyclinic.co.uk/images/pricktest.jpg


Oral Food Challenge
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Used to identify specific allergen if skin testing is not
conclusive and if keeping a food diary has failed to
determine the offending food items
Prep - eliminate suspected foods 7-14 days b4 test
Eat defined suspected allergen for at least 1 day
Monitor s/s of allergy
If with many food allergies – eat only 1 food type/day of
testing


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Laboratory tests
CBC
Increased eosinophils 12% (normal 1-2%)
Increased WBC count, but percentage of neutrophils is normal (55-70%)
Note: if acute infection occurs with rhinitis – both WBC and neutrophils
are increased)
Increased serum IgE
Only confirms the presence of infection
But does not indicate specific allergen
RAST (radioallergosorbent test)
Shows blood level of IgE directed against a specific antigen
Can determine specific allergies
Expensive

Management of Type I
Hypersensitivity Reaction
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Allergy management
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1. Avoidance therapy - identify and prevent exposure to
allergen, control of environment
2. Symptomatic therapy
1. Teach how to use Epi-pen
3. Desensitization therapy


1. Avoidance therapy
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Avoid direct contact with allergen
Airborne allergen
Air-conditioning and air cleaning units
Remove cloth drapes, upholstered furniture, carpet
Cover mattress and pillows with plastic or cotton fine mesh
Pet-induced allergy
Keep pet out of bedroom
Thoroughly clean room to remove hair and dander
Frequent bathing of pet


1. Avoidance therapy
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Avoid direct contact with allergen
Latex allergy
Avoid products with latex;
use synthetic substances that do not contain latex protein
Ex: Elastylite glove
Note: always use latex-free products in the care of client
with known latex allergy


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Drug therapy or Pharmaceutical approaches to allergy
treatment involve
Decongestants
Antihistamine
Corticosteroids
Mast cell stabilizers
Leukotrine Antagonists
Complementary and alternative Therapies
Aromatherapy
Eat unprocessed honey


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Nasal Decongestants
Action: prevent release of mediators such as histamine but do not
clear the allergen
Have similar action to adrenergic agents - cause vasoconstriction in
inflamed tissues
Often contain ephedrine, phenylephrine, or pseudoephedrine
Phenylephrine – 1 spray/nostril 4-6x/day ; Oxymetazoline -1
spray/nostril 2x/day ; pseudoephedrine (Sudafed)
Note: caution not to use more frequently than directed or for longer
than 4 days (overuse or continued use causes a rebound nasal
congestion or rebound rhinitis and worsens the symptoms)
S/E: dry mouth, increased BP, sleep difficulties

Nasal Spray
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Nasal Decongestants:
Nursing Implications

Decongestants may cause hypertension, palpitations, and
CNS stimulation—avoid in patients with these conditions
Patients on medication therapy for hypertension should
check with their physician before taking OTC
decongestants
Assess for drug allergies

Mosby items and derived items © 2005, 2002 by Mosby, Inc.

Nasal Decongestants:

Patients should avoid caffeine and caffeine-containing
products
Report a fever, cough, or other symptoms lasting longer
than a week
Monitor for intended therapeutic effects


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Antihistamine
Compete with histamine at receptor site and block histamine from
binding to the receptor –prevents vasodilation and capillary leak
first generation antihistamines
diphenhydramine (Benadryl) and chlorpheniramine (Chloratrimeton)
common side effect : sedation, drowsiness, and dry mouth
Use at night before bedtime to avoid feeling tired the next day.
second-generation antihistamines
loratadine (Claritin), fexofenadine (Allegra), and certirizine (Zyrtec)
less likely to cause drowsiness and can be taken during the daytime.


Antihistamines:

Gather data about the condition or allergic reaction that
required treatment; also assess for drug allergies
Contraindicated in the presence of acute asthma attacks
and lower respiratory diseases
Use with caution in increased intraocular pressure, cardiac
or renal disease, hypertension, asthma, COPD, peptic
ulcer disease, BPH, or pregnancy

http://www.chipola.edu/instruct/health-
sciences/PowerPointPresentations/Pharmacology/Chapter_035.ppt


Antihistamines:

Instruct patients to report excessive sedation, confusion, or
hypotension
Avoid driving or operating heavy machinery, and do not
consume alcohol or other CNS depressants
Do not take these medications with other prescribed or
OTC medications without checking with prescriber


Mosby items and derived items © 2005, 2002 by Mosby,
Inc.

Antihistamines:

Best tolerated when taken with meals—reduces GI upset
If dry mouth occurs, teach patient to perform frequent
mouth care, chew gum, or suck on hard candy (preferably
sugarless) to ease discomfort
Monitor for intended therapeutic effects



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Combined products
Claritin-D.
loratadine (Claritin) and pseudoephedrine (Sudafed) are combined in the
over-the-counter product
This allergy relief medicine gives the benefit of the antihistamine to
prevent nasal allergies and the decongestant to open swollen nasal passages.


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Corticosteroids
Decreased inflam and immune response in many ways
One way – prevent synthesis of mediators
Nasal spray – prevent symtpoms of rhinitis
Systemic – can produce severe S/E; avoised for rhinites; used inly
in short-term basis for other probmels assoc wth type I hypersen.
Beclomethasone (Beconase) –
1-2 metered spray /nostril ; 1-2x/day
fluticasone (Flovent, Flonase)
2 metered spray /nostril/day


Inhaled Corticosteroids:

Contraindicated in patients with psychosis, fungal
infections, AIDS, TB
Cautious use in patients with diabetes, glaucoma,
osteoporosis, PUD, renal disease, HF, edema
Teach patients to gargle and rinse the mouth with water
afterward to prevent the development of oral fungal
infections



Inhaled Corticosteroids:

Abruptly discontinuing these medications can lead to
serious problems
If discontinuing, should be weaned for 1 to 2 weeks, only
if recommended by physician
Report any weight gain of more than 5 pounds a week or
the occurrence of chest pain

sciences/PowerPointPresentations/Pharmacology/Chapter_036.p


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Mast cell stabilizers
Prevent mast cell membranes from opening when allergen bnds to
the IgE
Prevent symptomes of rhinits but not useful during acute episodes
cromolyn (NasalCrom, Intal)
1 spray/nostril/4-6x/day
Use as directed (effectiveness depends on regular use)
Start therapy 2-4 weeks b4 expected allergy season


Mast Cell Stabilizers:

For prophylactic use only
Contraindicated for acute exacerbations
Not recommended for children younger than age 5
Therapeutic effects may not be seen for up to 4 weeks
Teach patients to gargle and rinse the mouth with water
afterward to minimize irritation to the throat and oral
mucosa


Mosby items and derived items © 2005, 2002 by Mosby,
Inc.

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or Antileukotrienes
Also called leukotriene receptor antagonists (LRTAs)
Currently available agents
montelukast (Singulair)
zafirlukast (Accolate)
zileuton (Zyflo)
600mg 4x/day
Do not take with terfenadine or theophylline – Zyflo increases plasma
concentrations of these drugs


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Leukotrine
Substances in the body that cause inflammation, bronchoconstriction,
and mucus production
Result: coughing, wheezing, shortness of breath

Includes:
zileuton (Zyflo)


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zileuton (Zyflo)
600mg 4x/day
Do not take with terfenadine or theophylline – Zyflo increases plasma
concentrations of these drugs


2. Symptomatic therapy; Leukotrine Antagonists
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20 mg BID
Take 1 hr b4 or 2 hrs after eating (food
slows absorption of drug)
There is an increased incidence of URI
when co-administered with inhaled
corticosteroids (drug reduced local
inflam and immune response)
Reduce dose if also taking aspirin
(aspirin increases plasea concentration
of Accolate)


Antileukotrienes: Drug Effects

Keep bronchial airways relaxed (open)
Decrease mucus secretion
Prevent vascular permeability
Preventing inflammation


Mosby items and derived items © 2005,
2002 by Mosby, Inc.

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zileuton zafirlukast
Headache Headache
Dyspepsia Nausea
Nausea Diarrhea
Dizziness Liver dysfunction
Insomnia
Liver dysfunction
• montelukast has fewer side
effects



Antileukotrienes:

Ensure that the drug is being used for chronic management
of asthma, not
acute asthma
Teach the patient the purpose of the therapy
Improvement should be seen in about
1 week


2002 by Mosby, Inc.

Antileukotrienes:

Check with physician before taking any
OTC or prescribed medications—many
drug interactions
Assess liver function before beginning therapy
Medications should be taken every night on a continuous
schedule, even if symptoms improve


2002 by Mosby, Inc.

101

Complementary and alternative Therapies
Aromatherapy
Possible mechanism of action – competition and desensitization
Eat unprocessed honey
Indicated for those who have pollen allergies


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AKA:
Hyposensitization
Allergy shots
Indicated when allergens are identified
and cannot be avoided easily
Immunize with increasing doses of
allergen
Mechanism of action – competition


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Injection given
weekly -1st year
q other week – 2nd year
q 3-4 wks – 3rd year
5 years- recommended course of treatment
Or rally
Sublingual immunotherapy (SLIT)


Desensitization or Hyposensitization
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has been effective for a few antigens, particularly bee
venom.
is designed to cause an IgG response instead of an IgE
response.
The allergen is either ingested or injected into the subject
starting in small amounts and increased to larger amounts.


Desensitization or Hyposensitization
105

This treatment can have 2 effects:
1. T-helper 1 cells produce more IgG which binds to the
antigen so that it can’t bind to IgE receptors on mast
cells and cause release of histamines. – (Competition)
2. IgG binds to and removes the antigen before it binds to
T-helper 2 cells. The T- helper 2 cells will then not be
able to produce the B cells that will produce IgE.


Control of Type I Hypersensitivity Reactions
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Epinephrine
Increases cAMP levels and inhibits degranulation,
relaxes smooth muscles, increases cardiac output, and decreases
vascular permeability
Antihistamines
block the H1 and H2 histamine receptors on cells and
prevent degranulation


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Type II:
Cytotoxic hypersensitivity

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Antibody-mediated Cytotoxic Hypersensitivity

Complement-mediated lysis

Antibody dependent cell-mediated
cytotoxicity (ADCC)

Opsonization


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Hemolytic anemias
Hemolytic Transfusion Reactions
Hemolytic Disease of the Newborn
Drug-Induced Hemolytic Anemia


Transfusion Reactions
112

Due to antibodies that react with antigens on red blood cells
Transfused cells are killed by complement-mediated lysis


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ABO Blood Group System

Table 19.2


Figure 19.4

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Maternal IgG specific for red blood cell antigens crosses the
placenta and causes lysis.
The most severe form of the disease, called erythroblastosis
fetalis, develops in an Rh+ fetus carried in an Rh- mother.
Rh is an antigen found on red blood cells.


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Child with Rh hemolytic disease of the
newborn
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Why is the fetus edematous?
The child has hydrops fetalis.
Patients with Rh hemolytic disease
have severe anemias, which lead to
high output failure and both left
and right heart failure, the latter
responsible for peripheral edema
and ascites. The liver in this fetus
had massive hepatomegaly
secondary to extramedullary
hematopoiesis. http://www.duke.edu/~ema5/Golian/Slides/5/hematology11_files/Hem282.jpg


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Brain of the above fetus. What
is causing the yellowish
discoloration?
The yellow pigment is
unconjugated, lipid soluble
bilirubin derived from
macrophage destruction of the
Rh-sensitized fetal RBCs. The
condition is called kernicterus.


Kleihauer-Betke test in maternal blood post-
delivery
120
The mother is O negative The normal staining cells
and the baby is O positive. contain Hgb F and represent
Who do the normal fetal RBCs, while the pale
colored RBCs belong to staining cells contain Hgb A
and what should the from the mother. She should
mother be given to be given Rh immune
prevent sensitization? globulin (anti-D) to prevent
sensitization to the D
antigen.


Drug Induced Hemolytic Anemia
121

Antibiotics covalently attach to proteins on red blood cells
Penicillin, cephalosporin, Streptomycin
This essentially creates a hapten-carrier complex that can
result in a B cell response to the drug
Red-blood cells bound to the drug are killed by
complement-mediated lysis


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Drug (p=penicillin)
modified red blood cells
induce the production of
antibodies, because the
bound drug makes them
look foreign to the
immune system. When
these antibodies are
bound to them, the red
blood cells are more
susceptible to lysis or
phagocytosis. Onset is
dependent on the
presence of specific
antibodies.

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Symptoms:
Fever, chills, nausea, clotting within vessels and lower back pain.
Treatment:
Stop the transfusion! Or discontinue offending drug
Plasmapheresis
Filtration of plasam to remove specific subtances to remove antibodies
Symptomatic treatment
Provide diuretic to increase urine output and reduce buildup of hemoglobin
For Rh – mother
Should be given Rh immune globulin (anti-D) or RhoGam


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If mother has not yet been sensitized or exposed to the
Rh+ fetus,
She will be given an injection of Rh-immune globulin (Rhogam)at
about 28 weeks of pregnancy,
and within 72 hours after a birth, miscarriage, abortion, or amniocentesis.
If receive injection at 28 weeks and after delivery, sensitization will be
prevented and Rh incompatibility should not be a problem during your
next pregnancy.

http://www.pregnancy.org/article/rh-incompatibility-and-why-you-need-rhogam?page=1


125

The Rh-immune globulin contains antibodies to the Rh D
factor.
These antibodies will destroy any red blood cells from the baby that
have entered the mother’s blood.
The mother will not have a chance to form own antibodies to the Rh D
factor.



126

It is important to receive Rh-immune globulin in all cases
when the baby's blood could leak into the mother’s system,
including:
All pregnancies including ectopic (tubal) pregnancies
Early miscarriages
After chorionic villus sampling
After amniocentesis



127

How Long Will the Effects Last?
Sensitization usually doesn't happen until after the birth of an Rh-
positive baby.
Therefore, in most cases Rh incompatibility is not a problem during
a woman's first pregnancy and delivery of an Rh-positive baby.
However, later pregnancies and deliveries may be affected unless the
mother is treated with Rh-immune globulin after EVERY birth,
miscarriage, and abortion. Sensitization is permanent and the
effects are usually worse with each subsequent pregnancy.



Type III:
Immune complex-mediated
hypersensitivity

SERUM SICKNESS
SLE
RHEUMATOID ARTHRITIS
AGE

Type III hypersensitivity
129

Involve reactions against soluble antigens circulating in
serum.
Usually involve IgM, IgG antibodies.
Antibody-Antigen immune complexes are deposited in
organs, activate complement, and cause inflammatory
damage.
Glomerulonephritis: Inflammatory kidney damage.
Occurs with slightly high antigen-antibody ratio is present.


Type III hypersensitivity – immune complex formation
and deposition
130

Immune complexes
activate complement
Immune complexes of
(green dots- C3a, C4a, Inflammation and
antigen (red dots) and
and C5a), and mast cells edema occur, and
antibody form in
(yellow cell) degranulate. organ is damaged
target organ


Type III hypersensitivity – immune complex formation and
deposition
131

In sensitized individuals, allergen (antigen) combined with
antibody leads to the formation of immune complexes,
which activate complement and the inflammatory
response.
The location of the inflammation depends on the location
of the antigen - inhaled, under skin, systemic.
Onset is usually within 2-6 hours.


Type III (Immune Complex) Reactions

Figure 19.6

IgG antibodies and antigens form complexes that lodge in
basement membranes.

Serum sickness
133

Group of symptoms that occur after receiving serum or
certain drugs
Most common causes:
Penicillin
Other antibiotics
Some animal-based drugs
Less common- vaccines

Serum - does not contain white or red blood cells nor a clotting factor


134

s/s
7-12 days after receiving the causative agent
Fever arthralgia (achy joints)
Rash
Lymphadenopathy
Malaise
Polyarthritis and nephritis


SLE
135

Caused by immune-complexes lodged in :
Vessels(vasculitis)
Glomeruli (nephritis)
Joints (arthralgia, arthritis)
Other organs and tissues


Rheumatoid arthritis
136

Caused by immune-complexes lodged in joint spaces
followed by destruction of tissue , and later, scarring and
fibrous changes


Management
137

Usually self-limiting
Symptoms subside after several days
Antihistamine for itching
Aspirin for arthralgia
Prednisone if severe symptoms


Type IV:
Delayed Hypersensitivity

P P D ( P O S I T I V E P ROT E I N D E R I VA T I V E ) T E S T F O R T B
C O N TA C T D E R M A T I T I S
POISON IVY RASHES
LOCAL RESPONSE TO INSECT STINGS
TISSUE TRANSPLANT REJECTIONS

Type IV hypersensitivity – delayed-type or contact
139

T cells (blue cells) that
Antigen (red dots) recognize antigen are Inflammatory
are processed by activated and release response causes
local APCs cytokines tissue injury.

Antigen is presented by APCs to antigen-specific memory T cells that become activated and
produce chemicals that cause inflammatory cells to move into the area, leading to tissue injury.
Maria Carmela L.Domocmat, RN, MSN peaks by 24-48 hours.
Inflammation by 2-6 hours;

Type IV hypersensitivity
140

the only type that is not antibody-mediated.
This is the type involved in
contact hypersensitivity (poison ivy, reactions to metals in jewelry);
tuberculin-type hypersensitivity (the tuberculosis skin test);
and granulomatous hypersensitivity (leprosy, tuberculosis,
schistosomiasis and Crohn’s disease).


141

It is called delayed because its onset may vary;
the length of the delay varies from 72 hours in contact and
tuberculin-type to 21-28 days in granulomatous hypersensitivity.


142

In Type IV hypersensitivity, antigen presented by APCs
activates antigen-specific memory T cells (which have
been sensitized by prior exposure), causing them to
release cytokines that activate and attract other T cells and
phagocytic cells to the area. Where the source of antigen
is at the skin surface, the APC migrates from the dermis,
through lymphatic vessels to a lymph node in order to
present antigen to a T cell.


143

In the TB skin test, a small amount of soluble antigen
(tuberculin) is injected into the skin.
The T cells that are activated by the antigen secrete
cytokines that draw other cells to the site.
Within four hours, neutrophils have arrived, followed by
an influx of monocytes and T cells at about 12 hours.
The peak of activity is at about 48-72 hours, at which
point the area has become red and swollen.


144


145


Contact Hypersentivity

History and physical
examination provide
diagnostic clues

Jelly Fish Hypersensitivity

In this case, the
erythematous reaction
developed one week
after the contact with a
jelly fish

Acute Graft Rejection is a manifestation of
delayed hypersensitivity

Fluid Accumulation in Delayed Hypersensitivity Reactions

Patch test to identify the allergen for contact
eczema
151

Management
153

Removal of offending allergen
Reaction is self-limiting – 5-7 days
Monitor reaction site and sites distal for circulation adequacy
Corticosteroids or other anti-inflam
Benadryl is not recommended – bcoz histamine is not the main
mediator and IgE is not the cause


154


Have an allergy-free day!

155

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