Allergic reaction and anaphylaxis-risk workflow

Scope

Use for

Initial assessment of allergic reactions in outpatient settings before emergency transfer when indicated.

Not for

• Active airway compromise or circulatory instability requiring emergency response.
• Hospital-level post-anaphylaxis monitoring protocols.

Immediate actions

• Assess airway, breathing, circulation, skin/mucosa, GI symptoms, and exposure timing. Anaphylaxis can occur without hives or other skin findings.
• For suspected anaphylaxis, give IM epinephrine immediately and have someone call 911; do not wait for hypotension or a complete history.
• Use epinephrine 1 mg/mL: 0.01 mg/kg IM into the mid-anterolateral thigh, maximum 0.5 mg per dose. Repeat every 5 minutes if symptoms persist; record each dose and time.

Red flags: escalate now

If any of these are present, stop routine steps and follow the urgency stated. Activate emergency care for instability or findings that need immediate transfer.

• Tongue/throat swelling, wheeze/stridor, respiratory distress, hypotension/collapse, or rapidly developing multisystem symptoms after a likely allergen exposure.
• Transfer suspected anaphylaxis to hospital even after initial improvement; recurrence needs emergency reassessment.

First-line plan

• Keep the patient supine with legs elevated; do not let them stand or walk. Adjust for respiratory distress; use a lateral position for vomiting/unconsciousness and left side in pregnancy.
• Monitor continuously and support airway/breathing/circulation within available training and equipment. Antihistamines and inhalers do not replace epinephrine or delay transfer.
• Isolated mild skin symptoms require reassessment for progression before a symptom-control plan is chosen.

Follow-up and monitoring

• After emergency care, review trigger avoidance, anaphylaxis action plan, and epinephrine autoinjector access/technique; arrange allergy assessment.
• Record the suspected trigger, objective findings, treatment response, and hospital handover. Hospital teams determine observation duration.

Before the patient leaves

Return precautions you can say as written:

“If symptoms get worse, new warning signs appear, or you cannot follow the plan from this visit, seek urgent care now.”

• Point to the red flags above that apply to this patient.
• Confirm follow-up timing and where to go after hours.
• Attach a relevant handout to reinforce the plan.
• Document disposition, rationale, unresolved uncertainty, and that precautions were understood.

About this workflow

Clinical owner

Family Medicine Editorial Team

Risk tier

High

Review cadence

Every 3 months

Last reviewed

September 4, 2026AI-assisted evidence review. Clinical-owner sign-off is not recorded for this update.

Review status

Evidence current. Next review due December 4, 2026.

References

• World Allergy Organization Anaphylaxis guidance (2020) (opens in a new tab)
• PHAC Vaccine-associated anaphylaxis in community settings (opens in a new tab)
• CSACI Immunotherapy Manual 2024, anaphylaxis management (opens in a new tab)