Anaphylaxis is a medical emergency. If you think someone is having an anaphylactic reaction, the safest approach is to treat quickly and call 999. This page gives a clear, step-by-step emergency sequence you can follow under stress.

If you want the symptom recognition map that feeds into this emergency flow, keep Signs & Symptoms of Anaphylaxis (recognition) open here:

And if you’re building a complete readiness plan (assessment, access, and auto-injector options), start from Anaphylaxis Treatment (Adrenaline Auto-Injectors) Category Hub:

Table of Contents

First: confirm the “use adrenaline” threshold (fast)

Use adrenaline immediately if any of these are present:

Breathing problems (wheeze, shortness of breath, noisy breathing, persistent cough, trouble speaking)
Throat/airway symptoms (throat tightness, hoarse voice, trouble swallowing, tongue swelling)
Circulation symptoms (fainting, collapse, severe dizziness, pale/clammy)
Two or more body systems involved after a likely allergen exposure (for example hives + vomiting, or rash + breathing change)

This decision logic is explained in one place as a “yes/no rule” on When to Use an EpiPen (decision rule):

For children, recognition can look different use Anaphylaxis in Children: Symptoms & Fast Recognition:

Step-by-step anaphylaxis first aid (do this in order)

Step 1: Call it what it is “suspected anaphylaxis”

Don’t waste time debating labels. If the pattern fits breathing/throat/circulation or multi-system involvement, treat it as an emergency and move to action.

Step 2: Give adrenaline first (use the EpiPen)

If the person has an adrenaline auto-injector, give it immediately.

If you need the exact technique and handling steps, use How to Use an EpiPen (step-by-step):

Step 3: Call 999 (or ask someone else to call while you inject)

Say clearly:

“Suspected anaphylaxis”
Where you are
The person’s age (approximate is fine)
Whether adrenaline has been given (and what time)

While waiting for emergency services, continue the steps below don’t stop at the phone call.

Step 4: Position the person correctly (this is not optional)

Bad positioning can worsen collapse. Use this simple rule:

Positioning mini-table

Faint, dizzy, pale, weak → Lay flat (ideally legs raised)
Breathing is difficult → allow them to sit up slightly (but do not let them stand/walk)
Vomiting or unconscious → recovery position (on their side)
Pregnant (late pregnancy) → on the left side if possible (to reduce pressure on major blood vessels)

For the full positioning breakdown, read Correct Positioning (lay flat vs sit up):

Step 5: Monitor continuously (don’t assume “better” means “safe”)

Watch for:

worsening breathing
increasing throat symptoms
persistent dizziness or collapse
reduced responsiveness

If symptoms improve, still continue to emergency care anaphylaxis needs medical assessment.

Step 6: Know when a second dose may be needed

Some reactions don’t settle after the first dose, or symptoms return.

Use the timing guidance here: When to Use a Second EpiPen Dose (timing logic)

This “carry-two” reality is why many treatment plans are built around having two devices available. If you’re setting up a reliable emergency supply, the most common readiness option is EpiPen Adult 0.3mg Auto-Injector Twin Pack:

(With EpiPen Adult 0.3mg Auto-Injector Single used as a secondary option in specific situations):

Step 7: If the person becomes unconscious, start the CPR flow

If they are unresponsive, treat it as an immediate life threat and follow a CPR-first emergency flow.

Use this dedicated page: If Unconscious: CPR + Emergency Flow

The common mistakes that make outcomes worse

Delaying adrenaline to “try antihistamines first”
Letting the person stand or walk (can worsen collapse)
Assuming hives alone means anaphylaxis (sometimes it’s skin-only—use decision logic)
Waiting for “perfect” symptoms like collapse before acting
Not preparing for a second dose / not having a plan for recurrence

If your situation started as skin symptoms only, use the boundary guide: Hives Only vs Anaphylaxis (when it’s not systemic)
If it started as vomiting/diarrhoea, use: Vomiting/Diarrhoea + Allergy: When It Signals Anaphylaxis

What to tell paramedics (quick script)

Under stress, it’s easy to forget details. Use this structure:

“This is suspected anaphylaxis after [trigger if known].”
“Symptoms: [breathing/throat/collapse/vomiting/hives].”
“Adrenaline given at [time]. Dose number: [first/second].”
“Other meds: [if any].”
“History of allergies/asthma: [yes/no/unknown].”

Full handover prompts live here: What to Tell Paramedics (script + key facts)

After the emergency dose: what happens next?

Even if the person appears better, they still need medical review because symptoms can recur and monitoring is important after adrenaline.

Use the next-step: After Using an EpiPen: What Happens Next

Build a “ready before it happens” system (prevention inside emergency response)

Emergency outcomes improve when you remove friction before the moment hits. Two practical internal tools for that:

Emergency Allergy Kit Checklist:
Anaphylaxis Action Plan (checklist + printable logic):