Recognising Anaphylaxis for Student Nurses
Learn how to recognise the clinical pattern of anaphylaxis, assess airway, breathing and circulation changes and understand why rapid emergency escalation is essential.
What is anaphylaxis?
Anaphylaxis is a severe systemic hypersensitivity reaction that can develop rapidly. The clinical picture may involve airway swelling, breathing difficulty, circulatory compromise and changes in skin or mucous membranes.
Swelling or obstruction
Hoarse voice, difficulty swallowing, tongue swelling or noisy breathing may indicate airway involvement.
Respiratory difficulty
Breathlessness, wheeze, increased respiratory effort or falling oxygen saturation may occur.
Circulatory compromise
Tachycardia, hypotension, pallor, clamminess or collapse may indicate significant cardiovascular involvement.
Do not rely on a rash alone
Skin changes are common in allergic reactions, but anaphylaxis should not be ruled out simply because a rash is absent. The airway, breathing and circulation findings are particularly important.
| System | Possible findings | Why it matters |
|---|---|---|
| Airway | Hoarseness, throat tightness, tongue or facial swelling, stridor. | Progressive airway compromise can become rapidly life-threatening. |
| Breathing | Wheeze, breathlessness, tachypnoea, increased respiratory effort. | These findings may indicate significant respiratory involvement. |
| Circulation | Tachycardia, hypotension, dizziness, collapse, poor perfusion. | Cardiovascular compromise may indicate severe systemic reaction. |
| Skin | Flushing, urticaria, itching or swelling. | Skin signs may support recognition but are not essential for diagnosis. |
| Gastrointestinal | Abdominal pain, nausea or vomiting. | Gastrointestinal symptoms can occur as part of the wider reaction. |
| Neurological | Anxiety, confusion, dizziness or reduced responsiveness. | These changes may accompany hypoxia or circulatory compromise. |
Assess and act at the same time
In suspected anaphylaxis, assessment should not become a reason to delay emergency help. Use ABCDE while the appropriate clinical team is being summoned.
Airway
Assess for swelling, hoarseness, difficulty swallowing, stridor and other signs of threatened airway.
Breathing
Assess respiratory rate, oxygen saturation, wheeze, respiratory effort and ability to speak.
Circulation
Assess pulse, blood pressure, perfusion and signs of shock or cardiovascular collapse.
Disability
Assess consciousness and recognise new agitation, confusion, dizziness, collapse or reduced responsiveness.
Exposure
Look for rash, urticaria, flushing or swelling while maintaining dignity and continuing the emergency assessment.
Emergency escalation
Activate local emergency or resuscitation procedures immediately when anaphylaxis is suspected.
Recognition and escalation happen together
In a rapidly deteriorating patient, you do not need to complete every part of the assessment before calling for emergency help.
Consider what happened immediately beforehand
Anaphylaxis can follow exposure to a range of triggers. Understanding the recent clinical context can help recognition, but the priority is the patient's condition rather than identifying the precise trigger.
Drug exposure
Reactions may occur after medicines, including recently administered drugs.
Food exposure
Food allergens are a recognised cause of severe allergic reactions.
Wider exposure
Insect stings, latex and other allergens may also be associated with anaphylactic reactions.
Patterns requiring immediate concern
- Rapidly developing tongue, throat or facial swelling.
- New hoarseness, stridor or difficulty swallowing.
- Sudden wheeze or severe breathlessness.
- Increasing respiratory effort or difficulty speaking.
- Falling oxygen saturation.
- Rapid pulse with falling blood pressure.
- Dizziness, collapse or loss of consciousness.
- Sudden symptoms soon after medication, food or other possible allergen exposure.
- Airway, breathing or circulation changes even without obvious skin symptoms.
Think airway + breathing + circulation
The most important pattern is sudden systemic deterioration involving airway, breathing or circulation, particularly when it develops rapidly after a possible allergen exposure.
Putting the findings together
Example
A patient receives a medication and a few minutes later says their throat feels tight and they are struggling to breathe.
Their voice has become hoarse, their respiratory rate is increasing and they have developed widespread itching and facial swelling.
Their pulse is rapid and their blood pressure is beginning to fall.
The concern is the rapid onset of airway symptoms, breathing difficulty and circulatory deterioration after a possible trigger.
This requires immediate emergency escalation. As a student nurse, call for appropriate help, support an ABCDE assessment within your competence and follow the direction of the registered and emergency team according to local policy.
Anaphylaxis recognition errors to avoid
- Waiting for a rash. Severe anaphylaxis can occur without prominent skin signs.
- Underestimating throat symptoms. Hoarseness or swelling may indicate airway involvement.
- Assuming wheeze alone is asthma. Consider the wider clinical pattern and recent exposure.
- Waiting for profound hypotension. Earlier airway or breathing changes may already indicate severe deterioration.
- Trying to identify the exact allergen first. Emergency assessment and escalation take priority.
- Completing observations before calling for help. Do both concurrently when possible.
- Failing to report timing. Sudden symptoms after a new exposure are important information.
State clearly that you suspect an emergency
Example escalation
“I need urgent help. I'm concerned this patient may be having an anaphylactic reaction. Shortly after receiving medication they developed throat tightness, a hoarse voice and severe breathlessness. Their pulse is rapid and their blood pressure is falling.”
This communicates the suspected emergency, timing, airway and breathing symptoms, and circulatory deterioration.
Recognise → assess → communicate → escalate
Identify rapid systemic change
Look for sudden airway, breathing or circulatory problems, particularly after a possible trigger.
Use ABCDE immediately
Prioritise airway, breathing and circulation while continuing to assess the whole patient.
Call for emergency help
Clearly communicate that anaphylaxis is suspected and describe the patient's deterioration.
Build your emergency-assessment skills
Continue developing your ability to recognise acute deterioration, use ABCDE and communicate urgent concerns through the NurseNet Clinical Confidence pathway.
Explore Clinical Confidence →