Anaphylactic Response Flashcards
Types of hypersensitivity
Type 1: immediate hypersensitivity
- production of IgE antibody immediate.
- leads to vascular dilation, edema, smooth muscle contraction, inflammation
- associated w/ anaphylaxis, allergies and asthma
Type 2: antibody mediated hypersensitivity
- production of IgG, IgM which destroys cells and recruits leukocytes
- leads to inflammation and functional degeneration of tissues.
- associated w/ autoimmunity and good pasture syndrome
Type 3: immune complex mediated hypersensativity
- antigen-antibody complexes are deposited on tissue. Leads to leukocytes and compliment activation
- leads to inflammation and necrotizing vasculitis
- associated w/ SLE and serum sickness
Type 4: cell-mediated hypersensitivity
- T-lymphocytes relaxes inflammatory cytokines and macrophages
- leads to edema and granuloma formation
- associated w/ dermatitis, MS, TB and type 1 diabetes
What cells produce histamine, the primary mediator of anaphylaxis?
Mast cells and basophils
Sequence of events in immediate hypersensitivity reactions
Allergen exposure
Activation of TH2 cells and IgE class switch
Production of IgE
Binding of IgE to mast cells
Repeat exposure to antigen
Activation of mast cells and relapse of mediators
Immediate hypersensitivity reaction versus late phase reaction
Common triggers for anaphylaxis
Food allergies
Medications
Insect stings/bites
Latex
Opiates
Exercise
What is necessary to initiate an anaphylaxis response?
Sensitization to an offending agent
1) 1st exposure = NO REACTION
- IgE memory B cells form and are produced
- IgE binds to mast cells
2) 2nd exposure = instant degranulation of mast cells REACTION
Secondary anaphylaxis
Anaphylaxis response occurs later than expected (usually 2-48hrs after)
Systems affected during anaphylaxis and the symptoms associated
Skin (most common)
- hives
- itching
- flushing skin
- swelling
Airway (2nd most common)
- tightness of chest
- swelling of the throat
- scratchy throat
- dyspnea
- wheezing
Central nervous system (least common)
- anxiety
- headache
- dizziness
- confusion
- tunnel vision
- syncope
GI tract
- nausea
- abdominal cramping
- vomiting
- diarrhea
Cardiovascular system
- chest pain
- low BP (vasodilation)
- tachycardia
- syncope
Histamine effects in anaphylaxis
Affects all 5 organ systems
- is the prime mover of anaphylaxis
Primary action however is rapid dilation of blood vessels and induces hypotension
- if hypotension is <90/60mmHg, worry about it
also can induce dysrhythmias
Cysteinyl Leukotriens effects on anaphylaxis
Effects the respiratory and cardiovascular and integumentary systems
Platelet activating factors (PAFs) effects on anaphylaxis
Cardiovascular and integumentary systems
What are the two primary causes of death in anaphylaxis
Airway obstruction w/ hypoxia
- caused by inflamed airways or dysrhythmias / AV blocks
Hypotension
primary Treatment of anaphylaxis
Treat w/ adrenaline/epinephrine and oxygen saturation
- use fluid replacement when needed
Secondary additional treatment for anaphylaxis
For reduction of inflammation:
- Antihistamines and cortisone
To open airways better
- albuterol (beta agonist)
make sure to give epi-pens for home use and must be injected into the thigh (5x higher immediate serum concentration in thigh compared to arm)
What are quick relief asthmatic specific treatments?
- Short acting beta agonist: albuterol
- Ipratopium
- corticosteroids
- can use Leukotriene modifiers (singulair) for long term management*
What are potential life threatening results after treatment of anaphylaxis?
ST elevations
Secondary reactions
