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Anaphylaxis

(Anaphylactic Reaction; Severe Allergic Reaction)

Definition

Anaphylaxis is a severe, sometimes life-threatening, allergic reaction. It affects multiple organs, including the heart and lungs.
It is important to seek emergency medical care right away if you have symptoms of anaphylaxis.

Causes

Substances that cause anaphylaxis are often called allergens or triggers. Common triggers include:
Allergic Reaction to Medication (Hives)
Hives Medication
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Some triggers, like dyes used in x-ray procedures, can cause a reaction similar to anaphylaxis.

Risk Factors

Anyone can have anaphylaxis. Factors that may increase your risk of anaphylaxis include:

Symptoms

The symptoms of anaphylaxis usually occur within minutes after exposure to an allergen, but can occur hours later. Symptoms may be mild or severe, including death. They include:

Diagnosis

The diagnosis of allergy with a risk of anaphylactic reactions is made based on the patient’s history. Anaphylaxis will be suspected if you have symptoms and have been exposed to a likely allergen. It is important to see a doctor who specializes in allergies (allergist/immunologist). Skin tests and sometimes blood tests can done by allergy specialists to confirm the cause of the reaction.

Treatment

Anaphylaxis is a medical emergency that requires immediate medical treatment, including:
Note : If you receive emergency epinephrine, you should go to the emergency room right away, even if your symptoms have gone away.

Prevention

Avoiding substances that trigger anaphylaxis is the best prevention. In addition:

RESOURCES

American Academy of Allergy, Asthma, and Immunology http://www.aaaai.org

Food Allergy Research and Education http://www.foodallergy.org

CANADIAN RESOURCES

Allergy Asthma Information Association http://aaia.ca

Calgary Allergy Network http://www.calgaryallergy.ca

References

Anaphylaxis. Am Fam Physician. 2003 Oct 1;68(7):1339-1340. Available at: http://www.aafp.org/afp/20031001/1339ph.html. Accessed September 22, 2015.

Anaphylaxis. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated August 28, 2015. Accessed September 22, 2015.

Kay AB. Allergy and allergic diseases–second of two parts. N Engl J Med. 2001;344:109-113.

Lieberman P, Kemp SF, et al. The diagnosis and management of anaphylaxis: An updated practice parameter. J Allergy Clin Immunol. 2005 Mar;115(3 Suppl 2):S483-523.

Pumphrey R. Anaphylaxis: can we tell who is at risk of a fatal reaction?. Curr Opin Allergy Clin Immunol. 2004; 4:285.

Sampson, HA, Munoz-Furlong, A, et al. Second symposium on the definition and management of anaphylaxis: summary report—Second National Institute of Allergy and Infectious Disease/Food Allergy and Anaphylaxis Network symposium. J Allergy Clin Immunol. 2006;117:391.

Simons E. Anaphylaxis. J Allergy Clin Immunol. 2010;125: S161-81.

Winbery SL, Lieberman PL. Anaphylaxis. Immunol Allergy Clin North Am. 1995;15:447.

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