Anaphylaxis Flashcards
Briefly describe Anaphylaxis
- systemic hypersensitivity rxn
- serious allergic rxn
- rapid in onset
- could cause death
What % of anaphylaxis presents skin irritation?
80-90 %
Urticaria
Hives
Describe the pathophysiology of an immunologic anaphylaxis rxn
- during initial exposure an individual will transform IgE antibodies to an antigen
- when individual is exposed to antigen, it binds to IgE antibodies
- this triggers release of vasoactive and inflammatory mediators from mast cells and basophils
- ALSO RELEASES HISTAMINE
- leads to potential development of urticaria, angioedema, bronchospasm, hypotension, GI symptoms
When do symptoms usually occur after exposure?
30 mins (but could happen hours after)
angioedema
swelling
bronchospasm
difficulty breathing
hypotension
drop in BP
3 categories of human anaphylaxis
- immunologic (IgE mediated rxns)
- non immunologic (identical rxns that are not immunologically mediated)
- idiopathic (unknown cause)
understand clinical criteria
ok man
What are the 3 types of potential patterns of anaphylactic rxns?
- uniphasic (1 phase)
- biphasic (2 phases - symptoms reappear)
- protracted (severe rxn that lasts for more than 24 hrs)
What is recommended for Pt’s after they use an epipen?
seek medical attention
Describe examples of a cutaneous rxn to anaphylaxis
- hives/welts
- itching
- flushed/redness of the skin
- swelling
Describe examples of a respiratory rxn to anaphylaxis
- throat or chest tightness
- difficulty breathing
- wheeze
- cough
- swelling of tongue, lips, uvula, palate
- itching of throat
- itchy nose, congestion, runny/sneezing nose
Describe examples of GI rxn to anaphylaxis
- difficulty/pain swallowing
- nausea/vomitting
- abdominal cramping
- diarrhea
Describe examples of cardiovascular rxn to anaphylaxis
- hypotension (drop in BP)
- chest pain
- dysrhythmias (abnormal rhythm of the heart)
List a few other common rxns to anaphylaxis
*See pg 2/7 in notes
- lightheadedness
- dizziness
- sweating
- feeling of doom lol
- uneasiness
- headache
etc
etc
**children may display sudden behavioural changes
Give examples of common triggers of anaphylaxis
- foods
- drugs
- insect stings
- latex
List the 3 key parts of treatments for anaphylaxis in the community setting
- CPR (if breathing is affected)
- epinephrine (inj immediately and repeat in 10 mins if required)
- seek medical attention
What schedule are epinephrine auto injectors?
schedule 2 (don’t need an Rx, but held behind counter and require pharmacist consultation)
Describe the MOA (mechanism of action) of epinephrine auto injectors
- acts on alpha and beta-adrenergic receptors
- leads to restoration of respiratory and cardiovascular function by:
-relaxing bronchial smooth muscle (helps open airways)
-vasoconstriction to stop the vasodilation causing hypotension in anaphylaxis
(increase BP back to normal)
Where is the recommended administration of an epipen?
intramuscularly in the mid to outer part of thigh
Describe the action and duration of epipens?
rapid onset
short duration
When should pt’s feel improvement after injection of epinephrine?
5-10 mins
Why do we inject into the thigh?
-great blood supply
What is the dose for the adult epipen?
0.3mg/dose
What is the dose for the epipen jr?
0.15mg/dose
Are there any contraindications of epinephrine?
no absolute contraindications
What are a few common adverse effects of epinephrine?
- anxiety
- tremors
- pallor
- tachycardia (increase HR)
What is the acronym for what to watch for when expecting an allergic rxn?
FAST
Face - hives, itching, redness, swelling of face, lips, or tongue
Airway - restricted speaking, swallowing, or breathing
Stomach - stomach pain, vomiting, diarrhea
Total body - hives, itching, swelling, weakness
____ hives are present for less than 6 wks
acute
____ hives are recurrent with signs and symptoms recurring most days of the week, for six weeks or longer
chronic
Describe the appearance of hives
- smooth
- can be elevated
- discolored
itchy!
What can cause hives?
- allergic rxns
- infections
- illnesses
- exposure to sun, heat, cold, or water
- exercise
- stress
- contact w chemicals
- scratching the skin
Recommended treatment for acute urticaria?
oral anti-histamines
Describe general treatment of insect bites and stings (5)
- remove insect/stinger
- ice to reduce swelling
- clean area well
- non-Rx oral anti-histamines
- non-Rx topical steroid to relieve inflammation and itching
Describe the 6 OTC treatment options for insect bites and stings
- topical corticosteroids
- oral antihistamines
- skin protectants
- topical anesthetics
- topical antihistamines
- topical counterirritants
What is the difference between an anesthetic and an analgesic?
Anesthetic: induces insensitivity to pain
Analgesic: relieves pain
What do counterirritants do?
-depress cutaneous receptors resulting in relief of itching and irritation due to anesthetic
Do topical anesthetics have a short or long duration?
short (between 15 and 45 mins)
List some examples of topical anesthetics
benzocaine
lidocaine
pramoxine
What risk do topical anesthetics pose?
hypersensitivity rxn and systemic absorption/toxicity
T or F: drugs ending in “caine” are less common to pose a hypersensitivity risk than drugs with a different ending
false
-more common
How do topical antihistamines work?
They cause an anesthetic effect by DEPRESSING CUTANEOUS RECEPTORS to relieve pain and itching
What is more effective usually: oral or topical anesthetics
oral
Give an example of a topical antihistamine
topical diphenhydramine (benadryl)
What do skin protectants do?
reduce inflammation and irritation
Give 2 examples of skin protectants
zinc oxide
calamine
What are the 2 oral treatments for insect bites and stings
- analgesics (pain relief)
- oral antihistamines (relief of itching, inflammation and pain)
Give examples of oral analgesics (4)
- acetaminophen
- ASA
- naproxen
- ibuprofen
Antipruritic
anti-itch
explain how topical corticosteroids works
Produce antipruritic and anti-inflammatory actions that can prevent or suppress development of edema, capillary dilation, swelling and tenderness
Edema
fluid collection
Discuss the 5 monitoring parameters
- pain/fever
- itching
- swelling/redness
- signs of infection
- anaphylactic rxn
