Category: Pediatrics
Posted: 8/24/2012 by Mimi Lu, MD
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Types:
- Uniphasic anaphylaxis: occuring immediately after exposure to allergen, resolves over minutes to hours and does not recur
- Biphasic anaphylaxis: occuring after apparent resolution of symptoms typically 8 hours after the first reaction. Occur in up to 23% of adults and up to 11% of children with anaphylaxis
Treatment:
1. First line: IM epinephrine 1:1000 solution
- vasoconstrictor effects on hypotension and peripheral vasodilation; bronchodilator effects on upper respiratory obstruction
- NO absolute contraindication for use in anaphylaxis
- Dosage: Adult: 0.3 - 0.5mg; Peds: 0.01mg/kg (max 0.3mg)
- can be repeated every 5-15 minutes
2. Adjunctive therapy:
- H1 Blocker: diphenhydramine 1-2mg/kg up to 50mg IV
- H2 Blocker: ranitidine 1-2mg/kg
- Corticosteroid: 1-2 mg/kg for prevention of biphasic reactions
- Bronchodilator: Albuterol for bronchospasm
- Glucagon: for refractory hypotension or if patient is on beta blocker
- Dosage: Adult: 1-5 mg; Peds 20-30microgm/kg
- Dose may be repeated or followed by infusion of 5-15 mg/min
- place patient in recumbent position if tolerated with lower extremities elevated
- supplemental O2
- IV fluids for hypotension
Fatalities: typically seen with peanut or treenut ingestions from cardiopulmonary arrest. Associated with delayed or inappropriate epinephrine dosing
Disposition:
- Mild reaction with symptom resolution: observe for 4-6 hrs (ACEP, AAP)
- Recurrent symptoms or incomplete resolution: admit
Reference:
1. World Allergy Organization Guidelines for the Assessment and Management of Anaphylaxis, Feb 2011
2. Guidelines for the Diagnosis and Management of Food Allergy in the United States: Report of the NIAID-Sponsored Expert Panel Oct 2010
