What is the emergency management for a child with suspected anaphylaxis presenting with periorbital edema, lip swelling, rash, vomiting, and fever?

Emergency Management of Pediatric Anaphylaxis with Fever and Vomiting

Administer intramuscular epinephrine 0.01 mg/kg (maximum 0.3 mg for prepubertal children) into the mid-anterolateral thigh immediately—this is the only first-line treatment for anaphylaxis and must never be delayed. 1

Immediate Actions (First 60 Seconds)

Inject epinephrine first, then perform all other interventions:

• Give IM epinephrine 0.01 mg/kg of 1:1000 solution (maximum 0.3 mg) into the vastus lateralis muscle of the mid-outer thigh—this achieves peak plasma levels in 8±2 minutes versus 34±14 minutes with subcutaneous injection 1, 2
• Call for emergency medical services immediately while beginning treatment 1
• Position the child supine with legs elevated unless vomiting or respiratory distress makes this impossible 1, 2, 3
• Remove any identifiable allergen (stop food ingestion, remove stinger if present) 1, 2

Critical Recognition Point

The presence of vomiting plus periorbital edema, lip swelling, and rash meets diagnostic criteria for anaphylaxis (multi-system involvement with skin/mucosal plus gastrointestinal symptoms), making epinephrine administration mandatory regardless of whether fever is present 1, 4, 5

Addressing the Fever Component

Fever is NOT a typical symptom of anaphylaxis and suggests either:

• A concurrent viral illness that triggered the allergic reaction 1
• Flushing being misinterpreted as fever 4
• A separate infectious process occurring simultaneously 5

Do not delay epinephrine administration to investigate the fever—treat the anaphylaxis first, as delayed epinephrine is directly linked to anaphylaxis fatalities 1, 5

Repeat Epinephrine Dosing

Repeat IM epinephrine 0.01 mg/kg every 5-15 minutes if:

• Vomiting persists 1
• Respiratory symptoms worsen 1
• Cardiovascular symptoms develop (weak pulse, hypotension, altered consciousness) 1, 3, 4
• Any symptoms fail to improve within 5 minutes 1

Approximately 10-20% of pediatric patients require more than one epinephrine dose 2, 6, 7

Supportive Care (After Epinephrine)

Oxygen and Airway Management

• Administer 100% oxygen at 6-8 L/min for any respiratory symptoms 1, 2
• Prepare for advanced airway management if stridor, drooling, or severe respiratory distress develops 1, 2

Fluid Resuscitation

• Establish IV access immediately and give 20 mL/kg bolus of normal saline for cardiovascular symptoms (vomiting can indicate shock) 1, 2, 3
• Repeat fluid boluses up to 30 mL/kg in the first hour if hypotension persists 2, 3

Adjunctive Medications (Second-Line Only)

• H1 antihistamine (diphenhydramine 1-2 mg/kg IV/IM, maximum 50 mg) for urticaria/itching only—does NOT treat vomiting, airway obstruction, or shock 1, 2
• H2 antihistamine (ranitidine 1 mg/kg IV) may be added but has minimal evidence of benefit 1, 2
• Albuterol nebulizer (2.5-5 mg) only if bronchospasm persists after epinephrine 1, 2

What NOT to Do

Critical pitfalls to avoid:

• Never give antihistamines or corticosteroids before epinephrine—they have slow onset (4-6 hours) and do NOT prevent death from anaphylaxis 1, 2, 3
• Never delay epinephrine to establish IV access—IM injection is faster and equally effective 1, 2
• Never give subcutaneous epinephrine for anaphylaxis—absorption is too slow for shock treatment 3
• Never allow the child to stand, walk, or run—sudden postural changes can precipitate fatal cardiovascular collapse 2, 3
• Do NOT use the 1:1000 concentration intravenously—only 1:10,000 concentration is safe for IV use 1, 4

Observation and Disposition

Observe for minimum 4-6 hours after complete symptom resolution because biphasic reactions (recurrence without re-exposure) occur in up to 20% of cases, typically around 8 hours but up to 72 hours later 1, 2, 5, 7

Extended observation (≥6 hours) or admission is mandatory if the child:

• Required more than one epinephrine dose (strongest predictor of biphasic reaction) 1, 2
• Had severe initial presentation with vomiting plus cardiovascular symptoms 1, 2
• Has coexisting poorly controlled asthma 1, 5
• Is an adolescent with peanut/tree nut allergy 1
• Has unknown trigger 1, 2

Discharge Requirements (Mandatory for All Cases)

Before discharge, provide:

• Two epinephrine autoinjectors (0.15 mg for 10-25 kg; 0.3 mg for ≥25 kg) with hands-on training 1, 2
• Written anaphylaxis emergency action plan detailing symptoms, triggers, and when to inject epinephrine 1, 2
• Referral to allergist within 1-2 weeks for trigger identification 1, 2, 5
• Education about biphasic reaction risk with clear instructions to return immediately if symptoms recur 1, 2

Refractory Anaphylaxis Management

If hypotension or vomiting persists after 2-3 IM epinephrine doses:

• Consider IV epinephrine infusion 0.05-0.1 μg/kg/min (only with continuous cardiac monitoring) 1, 2, 3
• Administer IV epinephrine bolus 1 μg/kg (using 1:10,000 concentration only) for severe shock 1, 2
• Add vasopressor support (dopamine, norepinephrine) if hypotension persists despite epinephrine and fluids 1, 2

There are no absolute contraindications to epinephrine in anaphylaxis—the risk of death from untreated anaphylaxis far exceeds any potential epinephrine-related risk 1, 2