What is the management of an allergic reaction?

From the Guidelines

Management of Allergic Reactions

The management of allergic reactions involves prompt administration of epinephrine via an auto-injector, such as EpiPen or Adrenaclick, in a dose of 0.3-0.5mg intramuscularly, repeated as needed every 5-15 minutes 1.

• Antihistamines like diphenhydramine (25-50mg orally or intravenously) may be administered to alleviate mild symptoms, while corticosteroids like prednisone (40-60mg orally) may be given for severe anaphylaxis, asthma, and significant generalized urticaria/angioedema 1.
• In severe cases, oxygen therapy and intravenous fluids may be necessary to support vital functions, with close monitoring of vital signs and cardiac function for a minimum of 4-6 hours after the initial reaction 1.
• Glucagon should be available for epinephrine-unresponsive reactors, and atropine may be necessary to treat bradycardia 1.
• It is essential to note that antihistamines should not be used in place of epinephrine for severe symptoms, and patients should be advised to carry two epinephrine autoinjectors in case of an emergency 1.
• The importance of coadministering both H1 and H2 antihistamines is an emerging focus of anaphylaxis education to prevent severe cardiac deficit 1.
• Vital signs and physical examination should be repeated every 15 minutes or more frequently as needed for anaphylactic reactions until symptoms resolve and every 30 to 60 minutes after resolution until discharge 1.

From the FDA Drug Label

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. For amelioration of allergic reactions to blood or plasma, in anaphylaxis as an adjunct to epinephrine and other standard measures after the acute symptoms have been controlled, and for other uncomplicated allergic conditions of the immediate type when oral therapy is impossible or contraindicated.

The management of an allergic reaction includes:

• Epinephrine (IM) for emergency treatment of allergic reactions (Type I), including anaphylaxis 2
• Diphenhydramine (IV) as an adjunct to epinephrine and other standard measures after the acute symptoms have been controlled, for amelioration of allergic reactions to blood or plasma, and in anaphylaxis 3
• Other standard measures, although not specified in the provided drug labels.

From the Research

Management of Allergic Reactions

The management of allergic reactions, particularly anaphylaxis, involves several key steps:

• Removal of the trigger 4
• Early administration of intramuscular epinephrine [(4,5,6,7)]
• Supportive care for the patient's airway, breathing, and circulation [(4,8)]
• A period of observation for potential biphasic reactions [(4,8)]

Adjunct Medications

Adjunct medications may be considered after epinephrine administration, including:

• Histamine H1 and H2 antagonists 4
• Corticosteroids [(4,8)]
• Beta2 agonists 4
• Glucagon 4

Epinephrine Auto-Injectors

Epinephrine auto-injectors are recommended as the initial treatment of choice for anaphylaxis in the community [(5,7)]

• Personalized selection of epinephrine auto-injectors is influenced by individual factors, device properties, and cost 5
• There is currently no evidence to support customizable dose and needle length for epinephrine auto-injectors 5

Post-Anaphylaxis Management

After an anaphylactic reaction, management should focus on:

• Developing an emergency action plan 4
• Referral to an allergist 4
• Patient education on avoidance of triggers and appropriate use of an epinephrine auto-injector 4