Allergies Flashcards
What causes an allergic response?
B cells become hyperactive and increased amounts of immunoglobulins are produced causing a hypersensitivity
Hypersensitivity
an amplified or inappropriate response to an antigen leading to inflammation and destruction of healthy tissue
What are the two types of allergic reactions?
Atopic (local) and nonatopic disorders
Atopic disorders are characterized by what?
hereditary predisposition and production of local reaction to IgE antibodies
What are the 3 types of Atopic disorders?
- allergic rhinitis
- asthma
- atopic dermatitis/eczema
Nonatopic Reaction Examples
- tetanus vaccine
- insect venom
- airborne allergy
Nonatopic reactions lack what?
the genetic component and organ specificity of atopic disorders
A true latex allergy is considered to be what type of reaction?
type I hypersensitivity reaction
Contact dermatitis is considered to be what type of reaction?
type IV hypersensitivity reaction
Anaphylaxis
severe allergic reaction that is rapid onset and can cause various systemic reactions including death
Anaphylaxis is a clinical response to what type of reaction?
An immediate (type I hypersensitivity) immunologic reaction b/t specific antigen and an antibody
When does anaphylaxis occur?
when the body’s immune system produces specific IgE antibodies toward a substance that is normally nontoxic
When the body is re-exposed to the stimulating substance again it produces excess amounts of what protein?
histamine
Large amounts of histamine released in the body causes what?
- flushing
- urticaria
- angioedema
- hypotension
- bronchoconstriction
What are some common causes of Anaphylaxis?
- food
- medications
- other pharmaceutical/biologic agents
- insect stings
- latex
The severity of an anaphylactic reaction depends on what?
degree of allergy and dose of allergen
What are the three patterns of Anaphylactic reactions?
- uniphasic
- biphasic
- protracted
Uniphasic Reactions
occur as an exclusive incident where the patient develops symptoms w/in 30 minutes of exposure and resolve spontaneously w/in 1-2 hrs w/ or w/o meds
Biphasic Response
patient will have an initial reaction followed by subsequent symptoms up to 8 hours after
Biphasic response patients should be managed where?
emergency room
Protracted Response
may last for long period of time, up to 32 hours, and may include cardiogenic or septic shock and respiratory distress despite treatment
Mild systemic reactions consist of what symptoms?
- peripheral tingling
- sensation of warmth
- sensation of fullness in mouth/throat
- nasal congestion
- periorbital swelling
- pruritis
- sneezing
- tearing of eyes
Moderate systemic reactions may have what symptoms?
- flushing/warmth
- anxiety
- itching
- any of the milder symptoms
With more severe reactions you may see what?
- bronchospasm
- edema
- dyspnea
- cough
- wheezing
Mild and moderate reactions begin how long of exposure?
2 hours
Severe Systemic Reaction S/S
- abrupt onset w/ previous s/s
- bronchospasm
- larygeal edema
- severe dyspnea
- cyanosis
- hypotension
- dysphagia
- abdominal cramping
- n/v
- diarrhea
- seizures
What events may follow a severe systemic reaction?
cardiac arrest and coma
If the client is unable to avoid exposure to allergens they should be instructed to carry what?
Epinephrine
What route for medication administration is associated w/ the most severe anaphylactic reaction?
Parenteral
Insulin-allergic patients w/ diabetes and those allergic to penicillin may require what?
Desensitization
Desensitization
based on controlled anaphylaxis with a gradual release of mediators
What is the first line treatment of anaphylaxis?
Epinephrine
Why is Epinephrine the first line treatment?
it is the only medication that may halt cardiac or respiratory arrest
Cardiac or Respiratory Arrest typically occurs how long after exposure to allergen?
5-30 minutes
How is epinephrine given?
Sub q in the upper extremity or thigh
What other medications may be administered to prevent reoccurrence and to treat urticaria and angioedema?
Antihistamines and corticosteroids
