The mainstays of treating anaphylaxis are avoidance of the allergen when possible and emergency administration of epinephrine when necessary. For certain allergies, immunotherapy may be administered over time to desensitize the individual to the allergen.

 

Avoidance

Avoiding identified allergens is critical for people who suffer from severe allergies. People who may be susceptible to anaphylaxis should make a point to educate themselves about their allergen (see Food Allergy, Insect Venom Allergy, Latex Allergy, and Medication Allergy).

For example, those with food allergies should inquire about food ingredients that may provoke a reaction, and people who suffer from latex allergy should find out which consumer products contain latex. Many allergic reactions to drugs can be avoided by better communication among the physician, pharmacist, and patient—so be sure to ask your patients about any drug allergies they may have. People with insect venom allergies should take basic precautions with footwear, clothing, and the use of perfumes to minimize contact with bees, fire ants, or other stinging insects when engaging in outdoor activities.

It is also important that the allergic person's family, friends—and, in the case of children—teachers and schools know about and understand the ramifications of the allergy so that they can aid in preventing anaphylaxis.

 

Emergency Treatment

Severe allergic reactions are frequently unavoidable because foods may contain unknown ingredients, insects range widely, and latex can be found almost anywhere. Once anaphylaxis has begun, the treatment of choice is an immediate injection of epinephrine, sometimes called adrenaline, which is effective for 10 to 15 minutes, followed by emergency medical attention.1

Since there is no way to predict the severity of a reaction, and becauseanaphylaxis can progress so rapidly, waiting for the paramedics or ER staff toadminister epinephrine may greatly increase the risk of death. Therefore, it isessential that anyone with a history of anaphylaxis keep epinephrineauto-injectors, such as EpiPen® epinephrine auto-injectors, on hand at all times and be prepared to use them whenever a reaction occurs. Side effects of epinephrine may include palpitations, tachycardia (an abnormally fast heartbeat), sweating, nausea and vomiting, and respiratory difficulty. Cardiac arrhythmias may follow administration of epinephrine. Patients should ask their physician about the circumstances under which this life-saving medication should be used.

Epinephrine rapidly constricts the blood vessels, relaxes the muscles in theairway and lungs, reverses swelling, and stimulates the heartbeat, therebyreversing the most dangerous effects of an anaphylactic reaction. However, it does not replace medical help. Epinephrine provides the patient with emergency therapy, but immediate follow-up care by medical professionals will provide the patient the full treatment necessary to counter an anaphylactic episode. The sooner a patient receives epinephrine, the better that patient's chance of survival. Extra vigilance is also essential after an episode of anaphylaxis.

As many as 25% of people who have an anaphylactic reaction will experience a recurrence in the hours following the beginning of the reaction and will require further medical treatment, including additional epinephrine injections.2-4 This delayed reaction is called biphasic, meaning two phases.

The side effects of epinephrine may include palpitations, tachycardia, sweating, nausea and vomiting, and respiratory difficulty. Cardiac arrhythmias may follow the administration of epinephrine. Physicians should instruct their patients about the circumstances under which this life-saving medication should be used.

Many physicians also recommend that antihistamines, such as diphenhydramine, be administered to lessen the symptoms of an allergic reaction, but antihistamines should be taken only in addition to epinephrine for the treatment of anaphylaxis and should not be considered a substitute for it. Only epinephrine can halt the potentially deadly effects of anaphylaxis.

 

References

  1. AAAAI. The use of epinephrine in the treatment of anaphylaxis. Position statement #26. Available at: www.aaaai.org. 
  2. Stark BJ, Sullivan TJ. Biphasic and protracted anaphylaxis. J Allergy Clin Immunol. 1986;78:76. 
  3. Brazil E, MacNamara AF. "Not so immediate" hypersensitivity—the danger of biphasic anaphylactic reactions. J Accid Emerg Med. 1998;(4):252-253. 
  4. Korenblatt, et al. A retrospective study of the administration of epinephrine for anaphylaxis indicating need for more than one dose [abstract 234]. ACCP. 1998.