What is the treatment for an allergic reaction?

From the Guidelines

Treatment for an allergic reaction, particularly anaphylaxis, should always begin with the administration of epinephrine via an auto-injector, such as EpiPen, at a dose of 0.01 mg/kg of a 1:1000 solution to a maximum of 0.5 mg in adults and 0.3 mg in children, as this is the most effective and immediate way to reverse life-threatening symptoms 1. The most recent and highest quality study, published in 2020, emphasizes the critical role of epinephrine in managing anaphylaxis, highlighting that it is underutilized despite being the cornerstone of treatment 1. Key points to consider in the management of allergic reactions include:

• For mild to moderate reactions, antihistamines like diphenhydramine (Benadryl), cetirizine (Zyrtec), or loratadine (Claritin) can be used to alleviate symptoms such as itching, swelling, and hives.
• For skin reactions, applying 1% hydrocortisone cream to affected areas can help reduce itching and inflammation.
• In cases of anaphylaxis, after administering epinephrine, the person should lie down with legs elevated and call emergency services immediately.
• Identifying and avoiding the allergen is crucial for preventing future reactions.
• Antihistamines and corticosteroids may be used as adjunctive treatments but should not replace epinephrine in the management of anaphylaxis, as emphasized by studies from 2017 and 2011 1.
• The importance of educating patients and caregivers on how to administer epinephrine and the signs of anaphylaxis cannot be overstated, as prompt treatment is critical for preventing fatalities.
• Repeat dosing of epinephrine may be required for persistent or recurrent symptoms, and other medications like bronchodilators, H1 and H2 antihistamines, and corticosteroids may be considered in the management of severe reactions, as discussed in studies from 2013 and 2010 1.

From the FDA Drug Label

Adrenalin® is a non-selective alpha and beta adrenergic agonist indicated for: Emergency treatment of allergic reactions (Type 1), including anaphylaxis Emergency treatment of allergic reactions (Type I), including anaphylaxis, which may result from allergic reactions to insect stings, biting insects, foods, drugs, sera, diagnostic testing substances and other allergens, as well as idiopathic anaphylaxis or exercise-induced anaphylaxis.

The treatment for allergic reactions, including anaphylaxis, is epinephrine (IM). The dosage is as follows:

• Adults and Children 30 kg (66 lbs) or more: 0.3 to 0.5 mg (0.3 to 0.5 mL) intramuscularly or subcutaneously into the anterolateral aspect of the thigh every 5 to 10 minutes as necessary 2
• Children 30 kg (66 lbs) or less: 0.01 mg/kg (0.01 mL/kg), up to 0.3 mg (0.3 mL), intramuscularly or subcutaneously into the anterolateral aspect of the thigh every 5 to 10 minutes as necessary 2

From the Research

Treatment Options for Allergic Reactions

• Epinephrine is the first-line treatment for anaphylaxis, a severe and life-threatening form of allergic reaction 3, 4, 5
• Intramuscular epinephrine is the immediate treatment for all patients with anaphylaxis, while intravenous epinephrine should be used in patients in shock 4
• Antihistamines, such as H1 antihistamines, can be used to treat mild to moderate allergic reactions, including allergic rhinitis and urticaria 6, 7
• Corticosteroids may be used as adjunctive therapy in the treatment of allergic reactions, but their use should be revisited due to limited evidence on their effectiveness 5

Administration and Dosage

• Epinephrine should be administered promptly in the event of an anaphylactic reaction, with intramuscular injection being the preferred route of administration 3, 4
• Antihistamines can be administered orally or intranasally, with second-generation antihistamines being preferred due to their lower risk of sedation and impairment 6, 7
• The dosage and administration of corticosteroids in the treatment of allergic reactions should be carefully considered, as their use may be associated with increased risk of adverse effects 5

Special Considerations

• Biphasic reactions, which can occur hours after the initial reaction, should be considered when treating allergic reactions, and patients should be monitored accordingly 3, 4
• Patients with a history of allergic reactions should be educated on the proper use of epinephrine auto-injectors and antihistamines, and should carry these medications with them at all times 3, 6
• Healthcare professionals should be aware of the potential for antihistamine impairment and sedation, and should recommend non-sedating, non-impairing antihistamines whenever possible 7