4. HYPERSENSITIVITY Flashcards
Steve Johnson’s Disorder is what type of disorder
Hypersensitivity Disorders
Systemic Lupus Erythematosus is what type of disorder
Autoimmune Disorders
state of altered reactivity in which the body reacts with an exaggerated immune response to what is perceived as a foreign substance
Hypersensitivy
programmed to produce one specific antibody. On encountering a specific antigen, they stimulates production of plasma cells, the site of antibody production.
B cell, or B lymphocyte
assists the B cells in producing antibodie
T cell, or T lymphocyte
FUNCTION OF ANTIGENS
Two groups:
- Complete protein antigens
- Low-molecular-weight substances.
secrete substances known as lymphokines that encourage cell growth, promote cell activation, direct the flow of cell activity, destroy target cells, and stimulate the macrophages.
T cell, or T lymphocyte
FUNCTION OF ANTIGENS Two groups:
*such as animal dander, pollen, and horse serum, stimulate a
complete humoral response.
Complete protein antigens
FUNCTION OF ANTIGENS Two groups:
such as medications, function as haptens, binding to tissue or serum proteins to produce a carrier complex that initiates an antibody response.
Low-molecular-weight substances.
Types of Allergens
*Inhalants
*Ingestants
*Contactants
*Self Allergens
Two types of chemical mediators:
*Primary
*Secondary
type of chemical mediators:
are inactive precursors formed or released in response to primary mediators.
*Secondary
type of chemical mediators:
preformed and found in mast cells or basophils
*Primary
Classification of Hypersensitivity Reactions
- Type I - Immediate Hypersensitivity
- Type II - Cytotoxic/Cytolytic Hypersensitivity
- Type III - Immune Complex Disease
- Type IV - Delayed/Cell Mediated Hypersensitivity
Factors that affect the degree of hypersensitivity reactions:
- Responsiveness of host to allergen
- Amount of allergen
- Nature of allergen
- Timing of exposure to allergen
- Site of allergen-immune mediator reaction
- Host’s threshold reactivity
Classification of Hypersensitivity Reactions
- An exagerated immune response occurring in persons who have been previously sensitized to the specific antigen
- Inherited as a dominant trait
Sensitizing dose > Challenging dose > Allergic reaction
TYPE I: Immediate Hypersensitivity Reaction
This measures the levels of allergy antibody, or IgE, produced whhen your blood is mixed with a series of allergens in a laboratory
Blood Test
Classification of Hypersensitivity Reactions
Systemic life-threatening hypersensitivity reaction characterized by edema in many tissues and a fall in blood pressure secondary to vasodilation resulting from the intravascular presence of antigen introduced by injection, insect sting, or absorption across the epithelial surface of the skin or gastrointestinal mucosa.
Anaphylactic (Systemic) Reactions
Classification of Hypersensitivity Reactions
It occurs when the antigen is confined to a particular site by virtue of exposure.
*i.e allergic rhinitis; food intolernce
Atopic (Local) Reactions
- Characterized by symptoms of sneezing, itching and watery discharge from the eyes and nose
- Typical allergens may include pollens from grasses, weeds and trees; fungal spores; house dust mites; animal dander; feathers.
It is divided into 2 types:
* Perennial type-experience symptoms throughout the year
* Seasonal allergic rhinitis-plagued with intense symptoms in conjunction with periods of high allergen exposure
Allergic Rhinitis
It stabilizes mast cells and prevents degranulation when administered before expected contact with an allergen
Intranasal cromolyn
Type II: Cytotoxic/Cytolytic Hypersensitivity Reaction
Clinical Manifestations (Blood transfusion)
- Acute hemolytic
- Febrile, non-hemolytic
- Mild allergic
- Anaphylactic
it involves frequent (usually weekly) injections of the offending antigens- stimulate production of high levels of IgG which acts as a blocking antibody by combining with the antigen before it can combine with the cell-bound IgE antibodies.
Desensitization
Food Intolerance
*In children: ???
*In adults: ???
- milk, eggs, peanuts, soy, fish and shellfish foods
- peanuts, shellfish, and fish
- Blood test using immunoassay test to detect specific IgE Ab
- To determine the substances a subject is allergic to.
*Radioallergosorbent test (RAST)
Type III: Immune Complex Disease
Deposition of immunoglobulins, complement, and fibrinolytic products in blood vessels happens
Localized Immune Complex Reactions
Arthus reaction
Type II: Cytotoxic/Cytolytic Hypersensitivity Reaction
Medical Management
- Avoidance therapy
- Immunotherapy
- Medications
- Diet
Type II: Cytotoxic/Cytolytic Hypersensitivity Reaction
Diagnostic Procedures
*Serologic testing
*Urinalysis
Characterized by the formation and deposition of antigen-antibody complexes in various tissues which results in complement activation and inflammation
Type III: Immune Complex Disease
- Systemic Immune Complex Disorders: Serum Sickness
- Localized Immune Complex Reactions: Arthus Reaction
______ directly kill the antigen-presenting target cells that can lead to tissue injury by killing infected target cells even if the virus itself has no cytotoxic effects
Cytolytic T lymphocytes
- Confined to the skin initiated by re-exposure to an allergen to which a person had previously become sensitized (e.g. cosmetics, hair dyes, metals, topical drugs)
- The reaction does not become apparent for at least 12 hours and usually more than 24 hours after exposure and may last from days to weeks
Allergic Contact Dermatitis
Associated with exposure to inhaled organic dusts or related occupational antigens that may lead to chronic lung disease with minimal reversibilit
Hypersensitivity Pneumonitis
E.g. “farmer’s lung”- a condition resulting from exposure to moldy hay
Steven Johnsons Syndrome
Risk Factors
*Viral infections
*Immunocompromise
*Previous history
*Medications – allopurinol, carbamazepine
*Family history
Steven Johnsons Syndrome
Manifestations
- Skin Pain – most common
- Flu-like symptoms – malaise, fever, headache, Joint pain
- Rash – red to purple that spreads and form blisters
- Large blisters - painful sores after bursting
- Facial swelling and swollen lip
Steven Johnsons Syndrome
Diagnosis
- Physical Exam
- Medical history
- Biopsy – to confirm the diagnosis
Steven Johnsons Syndrome
Nursing Intervention
- Small frequent feeding
- Give analgesics
- Provide basic comfort measures
- Assess coping mechanism
- Educate about the disease
Steven Johnsons Syndrome
Medical Management
- NSAIDS
- Fluid replacement
- Topical corticosteroids
- Antibiotics
- Eyedrops
- Mouthwashes
- Cool moist compresses held against the skin
- Moisturizer
Systemic Lupus Erythematosus
Risk Factors
- Genetic
- Hormonal
- Environmental – sunlight
- Medications – hydralazine, isoniazi
Systemic Lupus Erythematosus
Clinical Manifestations
- Classical symptoms – fever, weight loss, pleuritis
- Musculoskeletal – arthritis (common), joint swelling, pain, tenderness
- Integumentary – butterfly rash
- Cardiovascular – pericarditis (common)
Systemic Lupus Erythematosus
Diagnosis
- History
- Physical Examination
Systemic Lupus Erythematosus
GOAL
- Prevent progressive loss of organ function
- Reducing likelihood of acute disease
- Minimize disease-related disabilities
- Prevention of complications
Systemic Lupus Erythematosus
Pharmacologic Management
- NSAID
- Corticosteroids – tab/IV
- Antimalarial drugs
- Immunosuppressive agents
Systemic Lupus Erythematosus
Nursing Management
- Cover
- Reduce stress
- Monitor for infection
- Refer to dietician
