Management of Urticaria and Itching After Allergic Food Consumption

Rationale for Epinephrine Use in Non-Anaphylactic Allergic Reactions

The American Academy of Pediatrics recommends erring on the side of injecting epinephrine rather than waiting too long, especially when symptoms occur after exposure to a known allergen 3
Generalized acute urticaria, while not immediately life-threatening on its own, warrants epinephrine administration in the context of a known food allergen exposure, as it may progress to anaphylaxis 1, 2
Prompt administration of epinephrine is key to preventing progression to more severe symptoms, as delayed administration has been implicated in contributing to fatalities 4
Individuals with food allergies, especially to peanuts, tree nuts, seafood, and milk, are at higher risk for severe reactions and should receive epinephrine promptly 4

For adults and children ≥30 kg: 0.3-0.5 mg epinephrine intramuscularly into the anterolateral thigh 5
Epinephrine doses may need to be repeated every 5-15 minutes if symptoms persist 6
Ringer's lactate (or other IV fluids) should be administered in large volumes if the patient presents with orthostasis, hypotension, or incomplete response to IM epinephrine 6

H1 antihistamine (diphenhydramine): 1-2 mg/kg per dose, maximum 50 mg IV or oral 6
H2 antihistamine (ranitidine): can be added as adjunctive therapy 6
Bronchodilator (albuterol): for bronchospasm if present 6
Supplemental oxygen therapy as needed 6
Place patient in recumbent position with lower extremities elevated if tolerated 6

All patients who receive epinephrine should be transferred to an emergency facility for observation 7
Observation period of 4-6 hours is recommended, as biphasic reactions can occur 4, 7

Serious adverse effects from epinephrine are generally not a concern for otherwise healthy individuals 1
Common and anticipated pharmacologic effects include transient pallor, tremor, anxiety, and palpitations 1
Caution is needed in patients with cardiovascular disease, those taking monoamine oxidase inhibitors or tricyclic antidepressants, and those with conditions like uncontrolled hyperthyroidism 7

Reluctance to use epinephrine due to fear of adverse effects or incorrect assessment of reaction severity 1, 3
Relying solely on antihistamines for treatment of allergic reactions after food exposure 1, 6