What is the follow-up management plan for a patient with a history of allergies, treated with epinephrine (adrenaline) and other supportive measures for anaphylaxis?

Follow-up Management After Anaphylaxis Treatment

All patients treated for anaphylaxis must be discharged with two epinephrine auto-injectors, a written emergency action plan, and a mandatory referral to an allergist-immunologist for comprehensive evaluation and trigger identification. 1

Immediate Observation Period

Patients require individualized observation based on severity and risk factors, with a minimum of 4-6 hours for most cases, extending to prolonged observation or hospital admission for severe reactions or those requiring multiple epinephrine doses. 1

• For patients without severe risk features who received single-dose epinephrine with complete symptom resolution, discharge after 1 hour of asymptomatic observation may be reasonable 1
• Extended observation up to 6 hours or longer (including hospital admission) is appropriate for patients with severe anaphylaxis, need for multiple epinephrine doses, cardiovascular comorbidity, lack of access to emergency services, or poor self-management skills 1
• Biphasic reactions (recurrence without re-exposure) can occur in up to 20% of cases, with risk factors including severe initial presentation, wide pulse pressure, unknown trigger, cutaneous manifestations, and drug triggers in children 1
• All patients must remain under observation until signs and symptoms have fully resolved, regardless of initial severity 1

Mandatory Discharge Requirements

Epinephrine Auto-Injector Prescription

Provide or prescribe two doses of epinephrine auto-injector before discharge—0.15 mg for patients weighing 10-25 kg and 0.3 mg for patients ≥25 kg. 1, 2

• Patients must carry auto-injectors at all times, as anaphylaxis is unpredictable and can occur with accidental allergen exposure 2
• Direct provision of the device is preferred over prescription alone, with instructions to fill prescriptions immediately if direct provision is not possible 1
• Establish a monitoring system for tracking auto-injector expiration dates (devices expire after 1 year) and ensure patients check that the liquid remains clear 1
• Auto-injectors are temperature-sensitive and must be stored at room temperature to prevent medication degradation 1

Written Emergency Action Plan

Provide a written anaphylaxis emergency action plan detailing symptom recognition and step-by-step treatment instructions, including proper epinephrine self-injection technique. 1, 2

• The plan should emphasize that delayed epinephrine administration is associated with fatalities, and injection should occur at the first sign of anaphylaxis 2
• Patients should be instructed to self-inject epinephrine at the first sign of symptom recurrence, then immediately call an ambulance or proceed to the nearest emergency facility 1
• Advise patients on the value of medical identification jewelry to easily identify themselves as having anaphylaxis potential and their specific allergen triggers 1

Adjunctive Medications Post-Discharge

Consider continuation of adjunctive treatment after discharge: H1 antihistamine (diphenhydramine every 6 hours or non-sedating second-generation antihistamine), H2 antihistamine (ranitidine twice daily), and corticosteroid (prednisone daily) for 2-3 days. 1

• These medications are not reliable interventions to prevent biphasic anaphylaxis but may be considered for secondary symptom management 1
• Glucocorticoids are not helpful acutely but may potentially prevent recurrent or protracted anaphylaxis in patients with idiopathic anaphylaxis or asthma 1

Allergist-Immunologist Referral (Mandatory)

Referral to an allergist-immunologist is mandatory for all patients post-anaphylaxis to identify triggers, coordinate diagnostic testing, and develop long-term management strategies. 1, 2

• Follow-up with the primary care professional should occur within 1-2 weeks after the anaphylactic event, with additional referral to an allergist-immunologist for comprehensive evaluation 1
• The allergist-immunologist should identify allergic triggers through comprehensive allergy diagnostic testing, including properly timed serum tryptase levels if the diagnosis is uncertain 1
• Consultation is particularly important when the diagnosis is doubtful or incomplete, symptoms are recurrent or difficult to control, the patient is a candidate for desensitization or immunotherapy, or anaphylaxis is complicated by comorbid conditions 1, 2

Specific Indications for Allergist Consultation

The allergist-immunologist provides critical services including: 1

• Evaluation of risks and benefits of therapeutic options, including allergen-specific immunotherapy (highly effective for insect venom anaphylaxis with 90-98% efficacy) 1
• Assessment for desensitization protocols (e.g., penicillin desensitization) 1
• Training and retraining in self-administration of epinephrine, as many patients demonstrate incorrect technique despite prior training 2
• Counseling on avoidance measures, which is the most effective treatment for most causes of anaphylaxis 1, 2

High-Risk Patient Identification

Adolescents and young adults, patients with concomitant asthma (especially poorly controlled or severe), and those with previous anaphylaxis or known allergy to peanuts, tree nuts, fish, or crustacean shellfish are at highest risk for fatal anaphylaxis. 2

• Patients with cardiovascular disease, those on beta-blockers, and elderly patients are at greater risk for severe reactions and complications 1, 3
• Patients with mast cell disorders, pheochromocytoma, hyperthyroidism, Parkinson's disease, or diabetes require special consideration 3

Patient Education and Trigger Avoidance

Provide printed information about anaphylaxis and its treatment, emphasizing intensive education on specific allergen avoidance based on identified triggers. 1

• For food allergies, education must cover reading labels, cross-contamination risks, and restaurant dining precautions 2
• Patients should be advised they are at risk for repeat episodes in the future and must understand the importance of subsequent testing to determine and verify triggers 1
• Avoidance management should consider age, activity, occupation, hobbies, residential conditions, and access to medical care 1

Common Pitfalls to Avoid

• Never discharge patients without epinephrine auto-injectors and proper training—this is associated with increased mortality 2, 4
• Do not rely on antihistamines or corticosteroids alone—these are adjunctive only and do not prevent biphasic reactions reliably 1
• Avoid premature discharge—observation periods must account for biphasic reaction risk, which can occur up to 72 hours after the initial event 5
• Do not skip allergist referral—trigger identification and long-term management planning are essential to prevent future life-threatening episodes 1, 2