What is the proper management and treatment for a patient experiencing an allergic reaction, and when should they go to the Emergency Department (ED)?

Patient Education for Allergic Reactions and When to Go to the Emergency Department

At the first sign of anaphylaxis symptoms, patients should immediately inject epinephrine into their outer thigh, and then call 911 or go directly to the nearest emergency facility—epinephrine administration should never be delayed while waiting for emergency services. 1

Recognizing When to Use Epinephrine and Seek Emergency Care

Signs That Require Immediate Epinephrine Use

Patients must inject epinephrine immediately if they experience any of the following after allergen exposure: 1

• Breathing difficulties: Wheezing, throat tightness, difficulty swallowing, or sensation of airway closing 1
• Cardiovascular symptoms: Rapid or weak pulse, drop in blood pressure, dizziness, fainting, or feeling like they might pass out 1, 2
• Skin reactions PLUS respiratory or cardiovascular symptoms: Hives or swelling combined with any breathing difficulty or lightheadedness 1, 3
• Severe gastrointestinal symptoms: Persistent vomiting, diarrhea, or abdominal cramping after known allergen exposure 2

Critical timing: Delayed epinephrine administration has been directly linked to fatal outcomes—in one study, 6 of 7 children who survived received epinephrine within 30 minutes, while only 2 of 6 children who died received it within the first hour. 1 Anaphylaxis can progress to death within 30-60 minutes without prompt treatment. 1

How to Use Epinephrine Auto-Injector

Injection Technique

• Inject into the outer thigh (vastus lateralis muscle) through clothing if necessary—this is the most effective site for rapid absorption 1, 2
• Never inject into buttocks, hands, feet, or digits due to risk of tissue damage 2
• Hold the leg firmly during injection, especially in children, to prevent movement-related injury 2

Dosing

• Adults and children ≥30 kg (66 lbs): 0.3-0.5 mg epinephrine 2
• Children <30 kg (66 lbs): 0.01 mg/kg, maximum 0.3 mg per dose 2
• Repeat dosing: May repeat every 5-15 minutes if symptoms persist or worsen 3, 2

When Emergency Department Evaluation Is Mandatory

All patients who use epinephrine must be transported to an emergency facility for observation, even if symptoms completely resolve. 1, 3 This is non-negotiable because:

• Biphasic reactions occur in 1-20% of cases, typically around 8 hours after initial symptoms but can happen up to 72 hours later 1, 3
• Observation period should be 4-6 hours minimum for most patients, with longer observation or admission for severe or refractory symptoms 3

Immediate Emergency Transport Required When:

• Any epinephrine dose has been administered 1
• Symptoms involve breathing difficulty or cardiovascular compromise 1
• Patient has asthma (higher risk for severe reactions) 1, 3
• Symptoms are not rapidly improving after first epinephrine dose 1

Essential Patient Education Components

The "SAFE" Framework

Educate all patients using this structured approach: 1

S - Seek Support:

• Patients are at risk for repeat anaphylaxis episodes in the future 1
• At first sign of symptom recurrence, inject epinephrine immediately, then call 911 1

A - Allergen Identification and Avoidance:

• Identify specific triggers through testing with an allergist 1
• Strict avoidance of confirmed allergens is essential 3
• Read all food labels carefully; inform restaurants, schools, and caregivers of allergies 1

F - Follow-up with Specialty Care:

• Schedule appointment with primary care provider within 1-2 weeks after anaphylaxis event 1
• Obtain referral to allergist/immunologist for comprehensive testing and ongoing management 1

E - Epinephrine for Emergencies:

• Always carry two epinephrine auto-injectors at all times 1
• Check expiration dates regularly (devices expire after 1 year) 1
• Ensure liquid inside device remains clear, not discolored 1
• Store at room temperature to prevent medication degradation 1

Written Action Plan Requirements

Every patient must receive: 1, 3

• Written anaphylaxis emergency action plan detailing when and how to use epinephrine 1, 3
• Two-dose epinephrine prescription filled immediately 1
• Instructions on recognizing early warning signs specific to their allergy history 1
• Medical identification jewelry to alert others of anaphylaxis risk 1

High-Risk Situations Requiring Extra Vigilance

Patients at Increased Risk for Severe Reactions:

• History of prior systemic allergic reaction (must carry epinephrine) 1
• Food allergy combined with asthma (must carry epinephrine) 1, 3
• Cardiovascular disease or older age (higher risk for severe outcomes) 1

Environmental Considerations:

• Schools and daycare: Ensure staff are trained, child has access to epinephrine, and allergen-free environment is maintained at meals 1
• Restaurants and social events: Always inform staff of allergies; avoid shared food 1
• Exercise: Exercise-induced anaphylaxis requires epinephrine availability during physical activity 2

Common Pitfalls to Avoid

• Never delay epinephrine while waiting for antihistamines to work—antihistamines are adjunctive only and have delayed onset 1
• Do not assume mild symptoms will stay mild—anaphylaxis can rapidly progress within minutes 1
• Never inject into the arm (deltoid)—thigh injection achieves higher and faster epinephrine levels 1
• Do not skip emergency department evaluation even if symptoms resolve after epinephrine—biphasic reactions are unpredictable 1, 3
• Avoid leaving epinephrine at home—the unpredictable nature of allergen exposure requires constant availability 1, 4

Recent Evolution in Anaphylaxis Management

While traditional guidance mandated immediate 911 activation for all epinephrine use, the 2020 anaphylaxis practice parameter supports a contextualized approach for certain low-risk patients who may observe response to epinephrine for up to 15 minutes before deciding on emergency transport. 5 However, this applies only to select patients with food-induced anaphylaxis who have mild symptoms that rapidly resolve. For most patients, especially those with respiratory or cardiovascular symptoms, immediate emergency transport remains the standard of care. 1, 5