Case 05 · Allergy and immunology
Anaphylaxis (drug-induced, on a beta-blocker)
A 46-year-old woman is five minutes into an IV ceftriaxone infusion for cellulitis when she becomes itchy, flushed and breathless. The infusion is still running. Recognise anaphylaxis, stop the trigger, give IM adrenaline, and treat the shock and bronchospasm while her beta-blocker blunts the response.
About this case
What you will practise
Learning objectives
- Recognise anaphylaxis from sudden airway, breathing or circulation problems, usually with skin changes, after a trigger.
- Stop the trigger, call for help and position a hypotensive patient flat with legs raised.
- Give IM adrenaline early at the correct dose and site, and repeat it after 5 minutes if ABC problems persist.
- Give IV fluids for shock, and recognise refractory anaphylaxis that needs expert help and an adrenaline infusion.
- Understand how a beta-blocker changes the picture, and when glucagon is considered.
- Plan tryptase sampling, observation, allergy documentation, reporting and follow-up.
Key decisions this case tests
- What comes first: adrenaline, or antihistamines and steroids?
- IM or IV adrenaline, and why an IV bolus is dangerous in a patient with a pulse.
- Is it safe to sit her up to help her breathing?
- When to repeat adrenaline, and when to call it refractory.
- When to call an anaesthetist for her airway.
Reference basis
- Resuscitation Council UK. Emergency treatment of anaphylaxis: Guidelines for healthcare providers, 2021.
- Cardona V et al. World Allergy Organization anaphylaxis guidance 2020. World Allergy Organ J 2020;13:100472.
Content version 1.0 · November 2026 · clinical review pending. See the Clinical content policy.
Before you start
The physiology is a simplified teaching model: the reaction, the adrenaline effect and the beta-blocker blunting are timed for learning, not prediction. Doses follow the cited guidelines but have not yet been signed off by a clinician.
Visle is for education only and is not medical advice. Anaphylaxis is a medical emergency: use an adrenaline auto-injector if one is prescribed and call emergency services immediately.
Ready for another emergency?
Case 04 puts you in charge of diabetic ketoacidosis, where fluids, insulin and potassium have to be balanced hour by hour.