From the Guidelines
If you're experiencing a severe allergic reaction, use an epinephrine auto-injector (EpiPen) immediately and seek emergency medical attention by calling 911, as recommended by the most recent and highest quality study 1. Allergic reactions occur when your immune system overreacts to a normally harmless substance (allergen).
- If you're experiencing a mild to moderate allergic reaction, take an antihistamine like diphenhydramine (Benadryl) 25-50mg or cetirizine (Zyrtec) 10mg immediately, as suggested by 1.
- For skin reactions, apply 1% hydrocortisone cream to affected areas 2-3 times daily.
- Remove yourself from the allergen if possible and monitor your symptoms closely. Some key points to consider:
- Epinephrine is the first-line treatment for anaphylaxis, and its administration should not be delayed, as emphasized by 1 and 1.
- The recommended dose of epinephrine is 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 stated in 1.
- People with known severe allergies should carry emergency medication at all times and wear a medical alert bracelet, as advised by 1.
- Identifying and avoiding your specific triggers is the best long-term strategy for preventing future reactions. It's essential to note that anaphylaxis is a life-threatening condition that requires immediate medical attention, and the use of epinephrine auto-injectors can be lifesaving, as highlighted by 1 and 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. The signs and symptoms associated with anaphylaxis include flushing, apprehension, syncope, tachycardia, thready or unobtainable pulse associated with hypotension, convulsions, vomiting, diarrhea and abdominal cramps, involuntary voiding, airway swelling, laryngospasm, bronchospasm, pruritus, urticaria or angioedema, swelling of the eyelids, lips, and tongue. Epinephrine (IM) is used for the emergency treatment of allergic reactions, including anaphylaxis. The signs and symptoms of anaphylaxis that epinephrine (IM) treats include:
- Flushing
- Apprehension
- Syncope
- Tachycardia
- Hypotension
- Convulsions
- Vomiting
- Diarrhea
- Abdominal cramps
- Involuntary voiding
- Airway swelling
- Laryngospasm
- Bronchospasm
- Pruritus
- Urticaria
- Angioedema
- Swelling of the eyelids, lips, and tongue 2
From the Research
Allergic Reaction Symptoms
- Urticaria, difficulty breathing, and mucosal swelling are the most common symptoms of anaphylaxis 3
- Symptoms can range from mild urticaria and swelling, to abdominal cramping, to respiratory collapse 4
- Anaphylaxis is a multisystem disorder that can manifest signs and symptoms related to the cutaneous, respiratory, cardiovascular, and gastrointestinal systems 5
Allergic Reaction Triggers
- The most common triggers are medications, stinging insect venoms, and foods; however, unidentified triggers occur in up to one-fifth of cases 3
- Food, insect stings, and medications are common causes of acute allergic reactions 4
- Known food allergy is present in 52.5% of patients with anaphylaxis 6
Allergic Reaction Management
- Epinephrine is life-saving and the only first-line medication in the management of anaphylaxis 7
- Epinephrine should be administered promptly once anaphylaxis is suspected, to minimize morbidity and mortality 7
- Antihistamines and corticosteroids are second-line medications and should never be given in lieu of, or prior to, epinephrine 5
- Patients treated with prehospital epinephrine were less likely to have uncontrolled reactions, receive intravenous fluids in ED, and to be admitted after the reaction 6
Allergic Reaction Treatment
- Acute management of anaphylaxis involves removal of the trigger; early administration of intramuscular epinephrine; supportive care for the patient's airway, breathing, and circulation; and a period of observation for potential biphasic reactions 3
- Adjunct medications include histamine H1 and H2 antagonists, corticosteroids, beta2 agonists, and glucagon, but should only be considered after epinephrine administration 3
- Aggressive fluid resuscitation should also be used to treat the intravascular volume depletion characteristic of anaphylaxis 5
Biphasic Reactions
- Patients should be monitored for a biphasic reaction (i.e., recurrence of anaphylaxis without reexposure to the allergen) for four to 12 hours, depending on risk factors for severe anaphylaxis 3
- Biphasic reactions are a concern in anaphylaxis management, and guidelines are available to help determine treatment and disposition 4