What medication is given to treat anaphylaxis with symptoms of itching, skin erythema, tongue edema, and hypotension?

Treatment of Anaphylaxis with Symptoms of Itching, Skin Erythema, Tongue Edema, and Hypotension

Epinephrine is the first-line medication and must be administered immediately to treat anaphylaxis presenting with itching, skin erythema, tongue edema, and hypotension. 1

Primary Treatment

• Epinephrine should be administered intramuscularly into the vastus lateralis (anterolateral thigh) at a dose of 0.01 mg/kg of 1:1000 concentration (1 mg/mL), with a maximum single dose of 0.5 mg in adults and 0.3 mg in children and teenagers 1
• Epinephrine acts on both alpha and beta-adrenergic receptors to reverse the life-threatening manifestations of anaphylaxis 2
• Through alpha-adrenergic effects, epinephrine lessens vasodilation and increased vascular permeability, helping to restore blood pressure 2
• Through beta-adrenergic effects, epinephrine causes bronchial smooth muscle relaxation, alleviates pruritus, urticaria, and angioedema 2
• Delay in administering epinephrine has been associated with anaphylaxis fatalities and increased risk of biphasic reactions 1

Secondary Treatments

After administering epinephrine, the following medications may be used as adjunctive therapy:

Antihistamines

• H1 antihistamines (diphenhydramine 1-2 mg/kg or 25-50 mg parenterally) can be administered as second-line therapy 1
• Antihistamines should never be used alone or as the initial treatment for anaphylaxis 1
• H1 antihistamines will address only cutaneous manifestations of anaphylaxis, none of which are life-threatening 1
• A combination of H1 antihistamines (diphenhydramine) and H2 antihistamines (ranitidine) is superior to diphenhydramine alone, but both are still second-line to epinephrine 1

Glucocorticoids

• Systemic glucocorticosteroids can be considered for patients with a history of idiopathic anaphylaxis, asthma, or those experiencing severe or prolonged anaphylaxis 1
• Glucocorticoids have no role in treating acute anaphylaxis given their slow onset of action 1
• If given, intravenous glucocorticosteroids should be administered every 6 hours at a dosage equivalent to 1.0-2.0 mg/kg/day 1
• Recent practice parameters recommend against the administration of glucocorticoids to prevent biphasic anaphylaxis 1

Additional Interventions for Severe Cases

• For hypotension refractory to volume replacement and epinephrine injections, consider vasopressor infusion such as dopamine 1
• For bronchospasm resistant to epinephrine, consider nebulized albuterol 1
• If the patient is on β-blocker therapy, consider glucagon infusion 1
• In cases of cardiopulmonary arrest, high-dose intravenous epinephrine may be required 1

Important Considerations

• Epinephrine is most effective when given immediately after the onset of anaphylaxis symptoms 3
• Multiple doses of epinephrine may be required if symptoms persist or recur 1
• All patients with anaphylaxis should be transported to an emergency department for further monitoring due to the risk of biphasic reactions 1
• Aspirin is not indicated in the treatment of anaphylaxis and may potentially worsen symptoms in patients with aspirin sensitivity 1

Common Pitfalls to Avoid

• Delaying epinephrine administration while waiting for antihistamines or glucocorticoids to take effect 4, 5
• Using subcutaneous instead of intramuscular injection of epinephrine, which delays absorption 1
• Administering intravenous epinephrine outside of a monitored setting (should only be used for cardiac arrest or profound hypotension unresponsive to IM epinephrine) 1
• Underutilization of epinephrine due to unfounded concerns about adverse effects 6, 5
• Relying solely on antihistamines or glucocorticoids for treatment of anaphylaxis 1, 7