Trigger and timing
food, drug, venom, latex, exercise/cofactor, ACE inhibitor
Prior reactions, asthma, mast-cell disease, beta blocker use
Voice change, dysphagia, wheeze, vomiting, syncope, abdominal cramps
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← All presentations
Anaphylaxis & Angioedema
Airway, breathing, circulation: epinephrine first when anaphylaxis is suspected.
Your objective: explain the approach, recognize important warning signs, then test your recall.
Abbreviations explained
- ACS
- Acute coronary syndrome
- OMI
- Occlusion myocardial infarction
- ECG
- Electrocardiogram
- PE
- Pulmonary embolism
- POCUS
- Point-of-care ultrasound
- QTc
- QT interval corrected for heart rate
- LBBB
- Left bundle branch block
- RBBB
- Right bundle branch block
- hs-cTn
- High-sensitivity cardiac troponin
- CTA
- Computed tomography angiography
- ICU
- Intensive care unit
Filter
The jobAirway, breathing, circulation: epinephrine first when anaphylaxis is suspected.
- Call for airway help early when voice, tongue, floor-of-mouth, or breathing changes appear.
- Give IM epinephrine promptly for suspected anaphylaxis per local protocol; do not delay for antihistamines or steroids.
- Observe according to severity, treatment response, comorbidity, and local policy; discharge only with education and an autoinjector plan where appropriate.
Anaphylaxis is a clinical diagnosis.
Skin findings may be absent; progression of airway, breathing, circulation, or severe gastrointestinal symptoms after an exposure is enough to act. Angioedema may be histamine-mediated or bradykinin-mediated and airway progression matters more than the label.
Anaphylaxis with airway/breathing/circulation involvement Critical
Key: IM epinephrine and resuscitation per local protocol; prepare for a difficult airway.
Rapidly progressive tongue/laryngeal angioedema Critical
Key: Voice change, drooling, stridor, or inability to manage secretions requires immediate expert airway planning.
Refractory shock Critical
Key: Escalate to monitored resuscitation and vasopressor/critical-care pathway after repeated IM treatment and fluids per protocol.
Bradykinin-mediated angioedema Emergent
Key: ACE-inhibitor or hereditary pattern may lack urticaria and respond poorly to antihistamines; airway management remains central.
Isolated urticaria Common
Key: No airway, breathing, circulation, or severe GI involvement; still give explicit escalation advice.
Tick what your patient has — the banner updates as you go.
Airway/voice/secretions; tongue, lips, face, and floor of mouth
Work of breathing, wheeze/stridor, perfusion and blood pressure
Skin may be normal—do not use absence of hives to rule it out
Immediate
- Continuous monitoring, repeat airway examinations, ECG/glucose as clinically indicated
- Treat first; testing is not required to diagnose anaphylaxis
Targeted
- Tryptase may support later specialist assessment but must never delay treatment
- Investigate alternative shock/airway diagnoses when the presentation is atypical
Discharge readiness
- Document trigger uncertainty, action plan, autoinjector teaching and allergy referral per local practice
Medication safety reminder
Use this as a first-pass prompt; verify all medications, doses, concentrations, contraindications, weight, pregnancy status, and local protocols before administration.
Check indication, allergy, route, renal/hepatic risk, interactions, monitoring, and local formulary.
Discharge
- Complete resolution after appropriate observation, with action plan, epinephrine-autoinjector pathway, trigger avoidance, and follow-up.
Admit / monitored observation
- Persistent symptoms, severe asthma, significant comorbidity, unreliable access to rescue treatment, or evolving angioedema.
Resuscitation / ICU / airway team
- Airway compromise, shock, refractory symptoms, or repeated epinephrine requirement.
Use objective reassessment and the local pathway.
Before the next decision · reassess and hand over
Use these learning prompts with the presentation’s pathway. They are not discharge criteria.
- Reassess: compare symptoms, observations and examination with the initial assessment and response to treatment.
- Warning signs for Anaphylaxis & Angioedema:
- Stridor, hoarseness, drooling, tongue/floor-of-mouth swelling
- Hypotension, syncope, cyanosis, severe wheeze
- Rapid progression or repeated epinephrine requirement
- Severe asthma or delayed presentation
- ACE-inhibitor/hereditary angioedema with voice change
- Reconsider: check unresolved findings and alternative explanations, including the pitfalls below.
- Escalate: communicate deterioration, uncertainty or needs beyond the current setting.
- Plan the transition: identify outstanding results, responsibility for follow-up, patient understanding and specific return advice.
Clinical Pearls
- Epinephrine is the first-line rescue treatment; adjuncts do not secure an airway or reverse shock.
- Angioedema is an airway trajectory problem—reassess repeatedly.
Pitfalls
- Using antihistamines or steroids instead of epinephrine for anaphylaxis.
- Waiting for rash before treating airway or circulatory involvement.
PRACTICE REFRESHER
Rapid recall
Test your first action and the dangerous diagnoses before revealing the answer.
01 · First move
Before you scroll, what needs to happen first?
Call for airway help early when voice, tongue, floor-of-mouth, or breathing changes appear.
02 · Immediate threats
Name at least two diagnoses that cannot wait.
Anaphylaxis with airway/breathing/circulation involvement · Rapidly progressive tongue/laryngeal angioedema · Refractory shock
PRIVATE TO THIS DEVICE
Your learning note
Capture a weak point, a teaching pearl, or a question to take to your next shift.
Review schedule starts when marked reviewed
Selected guidance · source check 2026-09-07. These 1 source links support selected teaching points, not a complete review of this topic. Check population, setting and local protocol before applying a recommendation.
- Rosen’s Emergency Medicine, 10th ed. — allergy, anaphylaxis and angioedema
- WAO anaphylaxis guidance; local anaphylaxis and difficult-airway protocols