Anaphylaxis & Urticaria Flashcards
Anaphylaxis definition:
“Anaphylaxis is a serious systemic hypersensitivity reaction that is usually rapid in onset and may cause death. Severe anaphylaxis is characterized by potentially life-threatening compromise in airway, breathing and/or the circulation, and may occur without typical skin features or circulatory shock being present”
What is Anaphylaxis?
an acute systemic, allergic rxn (immune system is involved)
that’s life-threatening
Will anaphylaxis present the same way all the time?
NO
Will anaphylaxis present the same way all the time in the same pt?
NO
What is key for anaphylaxis?
early recogn. of signs/sx’s is key
Skin signs/sx’s are _____ to be present during anaphylaxis
most likely
(~80% of cases)
What does the word anaphylaxis mean?
excessive protection
What is the pathophys for an immunologic rxn (anaphylaxis)?
- During an initial exposure, an individual will form IgE antibodies to an antigen = allergen (AGAINST the peanuts for ex).
- Subsequently, when the individual is exposed to the antigen, it will bind to the IgE antibodies. This triggers the release of vasoactive and inflammatory mediators (ex: histamine - often associated with inflammation, itching, swelling etc.) from mast cells and basophils.
- This leads to the potential development of urticaria (=hives), angioedema (=swelling of top layers; ex: throat swelling), bronchospasm, hypotension, and gastrointestinal symptoms
- Often signs and symptoms occur with 30 minutes after exposure, but sometimes may not appear for several hours
When do signs & sx’s occur?
Often signs and symptoms occur with 30 minutes after exposure, but sometimes may not appear for several hours
The World Allergy Organization has divided human anaphylaxis into three categories. List the three categories.
- Immunologic;
- Nonimmunologic;
- Idiopathic causes
What is the clinical criteria?
Any ONE of the following two criteria fulfilled
a. ACUTE ONSET OF AN ILLNESS (minutes to several hours) with the involvement of the skin, mucosal tissue or both AND at least one of the following:
* Respiratory compromise (such as: dyspnea, wheeze, bronchospasm, etc)
* Reduced blood pressure or associated symptoms of end-organ dysfunction (such as hypotonia/collapse, syncope, incontinence)
* Severe gastrointestinal symptoms (such as severe crampy abdominal pain, repetitive vomiting), especially after exposure to non-food allergens
b. ACUTE ONSET OF HYPOTENSION OR BRONCHOSPASM OR LARYNGEAL INVOLVEMENT after exposure to a known or highly probable allergen for that patient (minutes to several hours), even without the presence of the typical skin symptoms
What are the 3 different potential patters of anaphylactic rxns?
- Uniphasic
- Biphasic
- Protracted
Uniphasic:
isolated reaction with signs and symptoms usually appearing within 30 minutes of exposure to allergic and spontaneously settles or resolves with treatment, generally within 1 to 2 hours
Biphasic:
anaphylaxis reaction resolves, then symptoms begin again usually within 8 hours of first symptoms. Occurs in up to 20% of patients experiencing anaphylaxis
Protracted:
severe reaction that lasts for an extended time (24 to 32 hours)
How should be anaphylaxis sx’s gen. be treated with?
with epi & then go to hospital to treat further potential outcomes of the rxn
What are the body systems that expresses anaphylaxis signs & symptoms?
- Cutaneous rxns
- Respiratory rxns
- Gastrointestinal rxns
- Cardiovascular
- Other rxns
What are the signs & sx’s of CUTANEOUS rxns seen with anaphylaxis?
- hives or welts, severe itching, flushing or redness of the skin, swelling
What are the signs & sx’s of RESPIRATORY rxns seen with anaphylaxis?
- throat or chest tightness, difficulty breathing, wheeze, cough or swelling of the tongue, lips, uvula/palate, itching of the throat
- nose: itching, congestion, runny and sneezing
What are the signs & sx’s of GASTROINTESTINAL rxns seen with anaphylaxis?
- difficult or painful swallowing, nausea or vomiting, abdominal cramping, diarrhea
What are the signs & sx’s of CARDIOVASCULAR rxns seen with anaphylaxis?
- hypotension, chest pain, dysrhythmias
What are the signs & sx’s OTHER rxns seen with anaphylaxis?
- lightheadedness, dizziness, sweating, feeling of impending doom, uneasiness, headache, confusion, tunnel vision, uterine contractions
What type of signs & sx’s of anaphylaxis do CHILDREN also often show?
Children may have sudden behavioral changes (irritability, stop playing, cling to parent)
What are the TOP 3 signs & sx’s of anaphylaxis?
- Urticaria, angioedema (88%)
- Dyspnea, wheeze (47%)
- Dizziness, syncope, hypotension (33%)
What is the LEAST freq. sign & sx of anaphylaxis?
seizure (2%)
What are Age-Related Factors influencing anaphylaxis?
Infants - cannot describe their sx’s
Adolescents & young adults - increased risk-taking behaviour
Labor & delivery - risk from medications (ex: antibiotic to prevent neonatal group B strep infection)
Elderly - increased risk of fatality from medication & venom-triggered anaphylaxis
What are Concomitant Diseases factors influencing anaphylaxis?
- Allergic rhinitis & eczema
- Psychiatric illness (ex: depression)
- Mastrocytosis/clonal mast cell disorders
- CV diseases
- Asthma & other respiratory diseases
What are Concomitant Medications/Ethanol/Recreational Drug use factors influencing anaphylaxis?
- Ethanol / sedatives / hypnotics / antidepressants / recreational drugs
- B-adrenergic blockers, ACE inhibitors, NSAIDs
What are Co-Factors that Amplify Anaphylaxis?
- Exercise
- Acute Infection (ex: a cold or fever)
- Emotional stress
- Disruption of routine (ex: travel)
- Premenstrual status (females)
What are common triggers of anaphylaxis?
- Foods: (*may range regionally)
- Peanut, tree nut, shellfish, fish, milk, eggs, sesame, food additives
- Drugs: (warn pt’s of potential anaphylaxis with new drugs ~’s)
- Antibiotics, NSAIDS and biologics
- Insect Stings
- honeybees, yellow jackets, hornets ,wasps and fire ants
- Latex
Certain labelling is req’d in certain regions based on if it’s really common
What is the INITIAL Tx of Anaphylaxis in the Community Setting?
- Assess ABC: Airway, Breathing, Circulation
- Epinephrine (ASAP FOR BEST OUTCOME)
- Inject immediately intramuscularly in the lateral aspect of thigh (mid-outer thigh)
- Give at first sign of a known or suspected anaphylactic reaction
- Call 911: let them know someone is having a life- threatening allergic reaction
- A second dose of epinephrine may be needed if no improvement in symptoms, may be given 5 to 15 minutes after first dose (should have 2 ON HAND)
- Seek Medical Attention: patient must go to nearest hospital immediately (by ambulance if possible)
- b/c don’t know the progression
How should someone be while giving epi?
- Recommended when giving epinephrine to have person SIT OR LIE DOWN
- If not already lying down, then after epinephrine, person should be placed on back with legs elevated
- If patient lightheaded, should lie down with legs elevated.
- Same if patient loses consciousness: patient should be placed on their back with legs elevated.
- If person feels sick or vomits, they should be placed on their side to ensure airway is clear and they do not choke on vomit
What is the Mech. of Action of Epinephrine Autoinjectors?
Acts on alpha and beta-adrenergic receptors, leading to restoration of respiratory and cardiovascular function by:
* RELAXATION OF BRONCHIAL SMOOTH MUSCLE, which helps to open airways to relieve wheezing and dyspnea
* VASOCONSTRICTION to stop the vasodilation causing hypotension in anaphylaxis. Also leads to cardiac stimulation.
Where is the recommended admin of Epinephrine Autoinjectors?
intramuscularly in the mid to outer part of the thigh
Epinephrine Autoinjectors have _____ onset of action, but has a _____ duration
RAPID
SHORT
(why we want to get them to hospital within 10 min)
Why is Epinephrine Autoinjectors administered to outer leg?
good blood supply; gets in there fast
Epinephrine Autoinjectors are Schedule __ medication
2 - behind counter; doesn’t require prescription
What are ~ auto-injector delivery systems?
- EpiPen
- Allerject
- Emerade
EpiPen:
- EpiPen (0.3mg/dose)
- For adults and children weighing 30 kg or more
- EpiPen Jr (0.15mg/dose)
- Infants and children (15 kg to 30 kg)
- Contains a single dose of epinephrine
- Check expiry date/color change (of epi)
- Counsel even on refills (pt could forget when in emergency)
- offer education to anyone caring for that individual
Allerject:
- Allerject 0.3 mg
- For patients who weigh 30 kg or more
- Allerject 0.15mg
- For patients who weigh 15 kg to 30 kg
- Contains a single dose of epinephrine
- Check expiry date/color change
- Counsel even on refills
WALKS THEM THROUGH THE STEPS ALOUD WHILE USING
Emerade:
- Recently marketed in Canada (Oct. 2020)
- Available as:
- Emerade 0.5 mg/dose
- Emerade 0.3 mg/dose
- Recommended/Usual Dosing:
- Children over 30 kg: 0.3 mg
- Adults under 60 kg: 0.3 mg
- Adults over 60 kg: 0.3 mg to 0.5 mg depending on clinical judgement
- Each pre-filled pen delivers a single dose of epinephrine
- Check expiry date/color change
- Counsel even on refills
Are there contraindications with epinephrine?
“There are no absolute contraindications to the use of epinephrine in a life-threatening allergic situation”
What are the common adverse effects of Epinephrine?
- Anxiety
- Tremors
- Pallor
- Tachycardia
When should pt’s feel improvement when given epi?
within 5 to 10 minutes
Why do you have to go to hospital after anaphylaxis?
b/c can give pt more than just epi if needed
ex:
- oxygen & IV fluids
- supportive therapy (ex: salbutamol)
- IV epi
What are the 5 emergency steps for tx of anaphylaxis?
- Give epi at the 1st sign of a known or suspected anaphylactic rxn
- Call 911 & tell them that someone is having a life-threatening allergic rxn
- Give a 2nd dose of epi as early as 5 mins after the 1st dose if there is no improvement in sx’s
- Go to the nearest hospital right away (ideally by ambulance), even if sx’s are mild or have stopped
- the rxn could get worse or come back - Call emergency contact person
You are counselling AB..
About a penicillin prescription. AB tells you that she has heard that “lots of people are allergic to it” and wants to know what the reaction would appear.
What would you discuss with AB?
- may get rash
- sudden behavioural changes
- itchiness
- stomach pain/issues
etc.
What is the acronym for an allergic rxn?
Think FAST…
Face - hives, itchiness, redness, swelling of face, lips or tongue
Airway - trouble breathing, swallowing or speaking, nasal congestion, sneezing
Stomach - pain, vomiting, diarrhea
Total Body - hives, itchiness, swelling, weakness, dizziness, sense of doom, loss of consciousness
then ACT…
- give epi
- call 911
Urticaria definition
“development of wheals (hives), angioedema or both”
Urticarial hives usually have 3 features:
- Swelling of the centre (may be different sizes), normally with reflex erythema around the outside
- Itching or burning
- Temporary, with skin back to normal appearance within 30 minutes to 24 hours
Urticarial Angioedema usually:
- Acute, erythematous or skin coloured swelling of lower dermis and subcutis or mucous membrane
- May experience pain instead of itch
- Takes longer to resolve compared to hives (may take up to 72 hours)
How common is Urticaria?
Common disorder, approximately 20% of general population
What can Urticaria be considered?
- Acute – present for less than 6 weeks
- Chronic - is recurrent, with signs and symptoms recurring most days of the week, for six weeks or longer
What is the appearance of Hives?
- May be pale or brightly erythematous, encircled by erythema
- Elevated
- May be round or oval and vary in size
- Can coalesce with other lesions
- Intense itch, symptoms often seem most severe at night
What is the pathophys of Urticaria?
“Mediated by cutaneous mast cells in the superficial dermis. Basophils have also been identified in lesional biopsies. Mast cells and basophils release multiple mediators upon activation, including histamine(which causes itching) and vasodilatory mediators (which cause localized swelling in the uppermost layers of the skin).”
What is the cause of Urticaria?
may be caused by:
* Allergic reaction to :
* Such as: foods, medicines, insect bites and stings, animals, pollen, latex
- Infections
- Illnesses
- Exposure to sun, heat, cold or water (cold/hot urticaria)
- Exercise
- Stress
- Contact with chemicals
- Scratching the skin
What is a difference b/t anaphylaxis & urticaria?
something else would be present in anaphylaxis (not just hives)
When would you refer a pt when they are experiencing Urticaria?
- Differential diagnosis required
- Physical examination to determine underlying cause is outside of the scope of a pharmacist
– Example: recommended to complete a cardiopulmonary examination to ensure symptoms are not due to an infection or anaphylaxis - Refer suspected cases of anaphylaxis to emergency care immediately
- Immediate medical attention for patients experiencing:
- Angioedema
- Respiratory symptoms such as: distress, wheezing, stridor
- Hyperpigmented lesions, ulcers or urticaria that last longer than 48 hours
- Signs of a systemic illness (such as fever, jaundice, enlarged lymph nodes)
What is the recommended treatment for acute urticaria?
2nd gen antihistamines
