Outpatient setting

First-line treatment:

Intramuscular epinephrine (autoinjector)

10 to 25 kg (22 to 56 lb): 0.15-mg epinephrine autoinjector (anterolateral thigh)

> 25 kg: 0.3-mg epinephrine autoinjector (anterolateral thigh)

Intramuscular epinephrine (1: 1,000 solution)

0.01 mg per kg per dose (anterolateral thigh); maximum dose: 0.5 mg

Epinephrine doses may need to be repeated every five to 15 minutes

Adjunctive treatment:

Bronchodilator (short-acting beta2 agonist): albuterol metered dose inhaler (child: 4 to 8 puffs; adult: 8 puffs) or nebulized solution (child: 1.5 mL; adult: 3 mL) every 20 minutes or continuously as needed

H1 antihistamine: diphenhydramine, 1 to 2 mg per kg per dose; maximum dose: 50 mg intravenously or orally (oral liquid is more readily absorbed than tablets); a less sedating second-generation antihistamine may be used as an alternative

Supplemental oxygen therapy

Intravenous fluids in large volumes if patient presents with orthostasis, hypotension, or incomplete response to intramuscular epinephrine

Place the patient in recumbent position, if tolerated, with the lower extremities elevated

Hospital-based setting

First-line treatment:

Intramuscular epinephrine (autoinjector)

10 to 25 kg: 0.15-mg epinephrine autoinjector (anterolateral thigh)

> 25 kg: 0.3-mg epinephrine autoinjector (antero-lateral thigh)

Intramuscular epinephrine (1: 1,000 solution)

0.01 mg per kg per dose (anterolateral thigh); maximum dose: 0.5 mg

Epinephrine doses may need to be repeated every five to 15 minutes

Consider continuous epinephrine infusion for persistent hypotension, ideally with continuous noninvasive monitoring of blood pressure and heart rate; alternatives are endotracheal and intraosseous epinephrine

Adjunctive treatment:

Bronchodilator (short-acting beta2 agonist): albuterol metered dose inhaler (child: 4 to 8 puffs; adult: 8 puffs) or nebulized solution (child: 1.5 mL; adult: 3 mL) every 20 minutes or continuously as needed

Hospital-based setting

Adjunctive treatment:

H1 antihistamine: diphenhydramine, 1 to 2 mg per kg per dose; maximum dose: 50 mg intravenously or orally (oral liquid is more readily absorbed than tablets); a less sedating second-generation antihistamine may be used as an alternative

H2 antihistamine: famotidine, 1 to 2 mg per kg per dose; maximum dose: 75 to 150 mg intravenously or orally

Corticosteroids: prednisone, 1 mg per kg; maximum dose: 60 to 80 mg orally; or methylprednisolone, 1 mg per kg; maximum dose: 60 to 80 mg intravenously

Vasopressors (other than epinephrine) for refractory hypotension, titrate to effect

Glucagon for refractory hypotension, titrate to effect (child: 20 to 30 mcg per kg; adult: 1 to 5 mg); dose may be repeated or followed by infusion of 5 to 15 mcg per minute

Atropine for bradycardia, titrate to effect

Supplemental oxygen therapy

Intravenous fluids in large volumes if patients present with orthostasis, hypotension, or incomplete response to intramuscular epinephrine

Place the patient in recumbent position, if tolerated, with the lower extremities elevated

At discharge

First-line treatment:

Epinephrine autoinjector prescription (two doses) and instructions

Education on avoidance of allergen

Follow-up with primary care physician

Consider referral to an allergist

Adjunctive treatment:

H1 antihistamine: diphenhydramine every six hours for two to three days; a less sedating second-generation antihistamine may be used as an alternative

H2 antihistamine: famotidine, twice daily for two to three days

Corticosteroid: prednisone daily for two to three days