Diagnose the presence or likely presence of anaphylaxis.

Place patient in recumbent position and elevate lower extremities.

Monitor vital signs frequently (every two to five minutes) and stay with the patient.

Administer epinephrine 1:1,000 (weight-based) (adults: 0.01 mL per kg, up to a maximum of 0.2 to 0.5 mL every 10 to 15 minutes as needed; children: 0.01 mL per kg, up to a maximum dose of 0.2 to 0.5 mL) by SC or IM route and, if necessary, repeat every 15 minutes, up to two doses).

Administer oxygen, usually 8 to 10 L per minute; lower concentrations may be appropriate for patients with chronic obstructive pulmonary disease.

Maintain airway with an oropharyngeal airway device.

Administer the antihistamine diphenhydramine (Benadryl, adults: 25 to 50 mg; children: 1 to 2 mg per kg), usually given parenterally.

If anaphylaxis is caused by an injection, administer aqueous epinephrine, 0.15 to 0.3 mL, into injection site to inhibit further absorption of the injected substance.

If hypotension is present, or bronchospasm persists in an ambulatory setting, transfer to hospital emergency department in an ambulance is appropriate.

Treat hypotension with IV fluids or colloid replacement, and consider use of a vasopressor such as dopamine (Intropin).

Treat bronchospasm, preferably with a beta II agonist given intermittently or continuously; consider the use of aminophylline, 5.6 mg per kg, as an IV loading dose, given over 20 minutes, or to maintain a blood level of 8 to 15 mcg per mL.

Give hydrocortisone, 5 mg per kg, or approximately 250 mg intravenously (prednisone, 20 mg orally, can be given in mild cases). The rationale is to reduce the risk of recurring or protracted anaphylaxis. These doses can be repeated every six hours, as required.

In refractory cases not responding to epinephrine because a beta-adrenergic blocker is complicating management, glucagon, 1 mg intravenously as a bolus, may be useful. A continuous infusion of glucagon, 1 to 5 mg per hour, may be given if required.

In patients receiving a beta-adrenergic blocker who do not respond to epinephrine, glucagon, IV fluids, and other therapy, a risk/benefit assessment rarely may include the use of isoproterenol (Isuprel, a beta agonist with no alpha-agonist properties). Although isoproterenol may be able to overcome depression of myocardial contractility caused by beta blockers, it also may aggravate hypotension by inducing peripheral vasodilation and may induce cardiac arrhythmias and myocardial necrosis. If a decision is made to administer isoproterenol intravenously, the proper dose is 1 mg in 500 mL D5W titrated at 0.1 mg per kg per minute; this can be doubled every 15 minutes. Adults should be given approximately 50 percent of this dose initially. Cardiac monitoring is necessary and isoproterenol should be given cautiously when the heart rate exceeds 150 to 189 beats per minute.

Medical offices in which the occurrence of anaphylaxis is likely should consider periodic anaphylaxis drills.

Protocols for use in schools to manage children at risk of anaphylaxis are available through the Food Allergy Network. These protocols include materials for educating teachers, office workers, and kitchen staff in the prevention and treatment of anaphylaxis. Furthermore, patients should be given written information with suggested strategies for their own care.