What is the treatment for an allergic reaction?

From the Guidelines

For severe allergic reactions, epinephrine administered intramuscularly in 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 is the first-line treatment. This is based on the most recent and highest quality study available, which emphasizes the importance of prompt epinephrine administration in anaphylaxis management 1.

Key Considerations

• Epinephrine is the cornerstone of anaphylaxis management and should be administered immediately in cases of severe allergic reactions, without delay 1.
• The recommended dose of epinephrine is 0.01 mg/kg, up to 0.3 mg in children, and 0.3 to 0.5 mg in adults, depending on the severity of the reaction 1.
• Antihistamines and corticosteroids may be used as adjunctive treatments, but they should not replace epinephrine in the management of anaphylaxis 1.
• Patients with known severe allergies should carry epinephrine auto-injectors at all times and wear medical alert identification 1.

Management of Anaphylaxis

• For mild reactions, over-the-counter antihistamines like Benadryl (diphenhydramine) 25-50mg every 4-6 hours or Zyrtec (cetirizine) 10mg once daily may be used to reduce symptoms like itching, hives, and mild swelling.
• For severe allergic reactions, use an epinephrine auto-injector immediately in the outer thigh, then call emergency services (911) 1.
• After using epinephrine, the person should lie flat with legs elevated unless this causes breathing difficulty 1.

Prevention and Education

• Education on avoidance of allergen and follow-up with a primary care physician or an allergist is crucial for patients with severe allergies 1.
• Consider referral to an allergist for further evaluation and management of allergies 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 is epinephrine (IM), specifically:

• Dosage: 0.3 to 0.5 mg (0.3 to 0.5 mL) intramuscularly or subcutaneously into anterolateral aspect of the thigh every 5 to 10 minutes as necessary for adults and children 30 kg (66 lbs) or more.
• Dosage for 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 anterolateral aspect of the thigh every 5 to 10 minutes as necessary. 2 2

From the Research

Allergic Reaction Treatment

• The primary treatment for anaphylaxis, a life-threatening systemic allergic reaction, is intramuscular epinephrine administration 3, 4, 5, 6.
• Epinephrine is considered the drug of choice for anaphylaxis, with no absolute contraindications in this clinical setting 6.
• Additional treatments may include histamine H1 and H2 antagonists, corticosteroids, beta2 agonists, and glucagon, but these should only be considered after epinephrine administration 3, 4.
• Patients should be monitored for a biphasic reaction, which can occur within 4 to 12 hours after the initial reaction, depending on risk factors for severe anaphylaxis 3, 5.
• The use of antihistamines and corticosteroids in anaphylaxis management is still being studied, with some evidence suggesting a beneficial effect of antihistamines, but corticosteroid use should be revisited 7.
• Airway obstruction must be recognized, and early intubation may be necessary in severe cases 5.
• Disposition depends on patient presentation and response to treatment, with mandatory observation periods not necessary due to the unpredictability of biphasic reactions 5.

Treatment Guidelines

• The World Allergy Organization recommends epinephrine as the first-line treatment for anaphylaxis 6.
• The American Family Physician journal suggests that clinicians can obtain serum tryptase levels to reflect mast cell degranulation when the clinical diagnosis of anaphylaxis is not clear 3.
• The Emergency Medicine Practice journal reviews the current evidence on managing allergy and anaphylaxis with epinephrine and other adjunctive therapies 4.
• The Immunology and Allergy Clinics of North America journal discusses the emergency department treatment of anaphylaxis, including the use of intravenous epinephrine and fluid resuscitation 5.

Patient Management

• Patients should be educated on avoidance of triggers and appropriate use of an epinephrine auto-injector 3.
• An emergency action plan should be developed, and patients should be referred to an allergist for further management 3.
• Patients who receive prehospital epinephrine are less likely to have uncontrolled reactions, receive intravenous fluids, and be admitted to the hospital 7.