Anaphylaxis Recognition in Pharmacy
How community pharmacists can rapidly recognise anaphylaxis, act on airway, breathing, and circulation signs, and escalate to 999 without delay.
Why this matters
Anaphylaxis is a rapid-onset, life-threatening hypersensitivity reaction that can become fatal within minutes. Community pharmacists are at the front line of allergen exposure through immunisations, dispensing new medicines, and providing food or drug allergy advice, and are often the first healthcare professional a patient reaches when a reaction begins.
The treatment window is narrow. Intramuscular adrenaline is the first-line treatment for anaphylaxis and should not be delayed while waiting for antihistamines, inhalers, or medical review. Antihistamines alone are never adequate treatment for anaphylaxis, and delays in recognising and treating the condition can be life-threatening.1
Recognise anaphylaxis by sudden onset and rapid progression of airway, breathing, or circulation problems, with or without skin or mucosal features. Recent exposure to a likely allergen supports the diagnosis, but a confirmed trigger is not required before calling 999 and giving intramuscular adrenaline when the clinical picture is strongly suggestive.2 Skin or mucosal features such as urticaria or angioedema may support the diagnosis but may be absent in up to 20% of cases.
Underestimation is the key danger. Presentations without urticaria or without a clear trigger are easily missed, and initial improvement can occasionally be followed by a biphasic reaction several hours later.
Red flags vs More likely benign
| Feature | More likely benign | Red flag ⚠ |
|---|---|---|
| Onset | Gradual over hours; mild and localised; not associated with a recent allergen exposure | Rapid onset within minutes of a likely trigger; symptoms escalating |
| Airway | Isolated mild nasal congestion unrelated to allergen exposure. Any throat symptoms after allergen exposure require urgent emergency assessment regardless of apparent severity. | Stridor, hoarse voice, tongue swelling, throat tightness, or difficulty swallowing |
| Breathing | Stable known asthma with usual symptoms when no allergen exposure has occurred. Worsening wheeze after allergen exposure should raise suspicion of anaphylaxis even in known asthma. | Acute wheeze, breathlessness, raised respiratory rate, cyanosis |
| Circulation | Flushed or warm; normal pulse; no systemic features | Tachycardia, pallor, clamminess, hypotension, syncope, or collapse |
| Skin / mucosa | Isolated, non-progressive hive or itch at the contact site only, with no airway, breathing, circulation, gastrointestinal, or systemic features. Monitor closely for any progression. | Generalised urticaria or angioedema; note that skin signs may be absent in up to 20% of anaphylaxis cases |
| Gastrointestinal | Mild nausea; no systemic features; no allergen exposure | Sudden abdominal cramps or vomiting alongside airway, breathing, or circulation symptoms |
| Trigger | Known mild intolerance with no history of systemic reaction | Recent exposure to a likely allergen such as food, medicine, insect sting, or latex before airway, breathing, circulation, gastrointestinal, or systemic symptoms. Absence of a known trigger does not exclude anaphylaxis. |
| Patient state | Anxious but alert, normal colour, no systemic features | Sense of impending doom, sudden anxiety, agitation, confusion, or collapse |
What to do in pharmacy
Do not move a patient who is faint, breathless, confused, or unstable to the consultation room. Bring the emergency kit to the patient.
Adrenaline is the immediate treatment. Use immediately available adrenaline without delay, following your pharmacy emergency standard operating procedure and current Resuscitation Council UK age-appropriate intramuscular dosing guidance.1 If only the patient's own adrenaline autoinjector is available, administer it into the outer mid-thigh according to the device instructions. If pharmacy-held adrenaline is available and staff are trained in its use, administer intramuscular adrenaline 1:1000 into the anterolateral thigh following RCUK dosing guidance. Do not delay administration while awaiting 999 call-handler confirmation.
Position: lay the patient flat with legs raised. Do not allow them to stand or walk. If breathing is difficult, allow sitting with legs extended. Do not allow sudden position changes even if the patient feels better, as sudden standing after adrenaline can precipitate collapse. If the patient becomes unconscious but is breathing normally, place them in the recovery position. If unconscious and not breathing normally, start CPR and use an AED if available.
If symptoms do not improve after 5 minutes, or if airway, breathing, or circulation symptoms return, give a second dose of adrenaline if available and continue to follow 999 call-handler instructions.
While awaiting the ambulance: assign one team member to stay with the patient, one to call 999, and one to meet the ambulance at the entrance. If oxygen is available and staff are trained in its use, give high-flow oxygen. Document and hand to the ambulance crew: onset time, suspected trigger, symptoms observed, airway, breathing, and circulation findings, adrenaline device and dose used, time of first and any second dose, and the patient's response.
Key takeaways
- Suspected anaphylaxis is a 999 emergency. Use immediately available adrenaline without delay, following your pharmacy SOP and RCUK intramuscular dosing guidance. Antihistamines are not a substitute.
- A confirmed trigger is not required before acting. Airway, breathing, or circulation compromise with rapid onset is sufficient to call 999 and give adrenaline. Skin signs may be absent in up to 20% of cases.
- All suspected anaphylaxis requires hospital assessment. Symptoms can recur hours after apparent recovery (biphasic anaphylaxis), and NICE NG258 requires risk-stratified observation and specialist allergy referral after emergency treatment.
📚 References
- Resuscitation Council UK. Emergency treatment of anaphylaxis: guidelines for healthcare providers. London: RCUK; 2021. https://www.resus.org.uk/reaction/anaphylaxis-guidelines
- National Institute for Health and Care Excellence. Anaphylaxis: assessment and referral after emergency treatment. NICE guideline NG258. London: NICE; 2026. https://www.nice.org.uk/guidance/ng258
- Resuscitation Council UK. Resuscitation guidelines 2025: special circumstances, anaphylaxis. London: RCUK; 2025. https://www.resus.org.uk/library/2025-resuscitation-guidelines
- Joint Formulary Committee. Adrenaline/epinephrine. British National Formulary. London: BMJ Group and Pharmaceutical Press. https://bnf.nice.org.uk/drugs/adrenalineepinephrine/
- Muraro A, Worm M, Alviani C, et al. EAACI guidelines: anaphylaxis. Allergy. 2022;77(2):357-377. https://onlinelibrary.wiley.com/doi/10.1111/all.15032
- National Institute for Health and Care Excellence. Anaphylaxis. NICE Clinical Knowledge Summary. London: NICE; 2023. https://cks.nice.org.uk/topics/anaphylaxis/
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Disclaimer: For educational use by healthcare professionals only. Does not replace clinical judgement, local pathways, or NICE guidance. Not for public self-diagnosis.