What is Anaphylaxis?
It is a severe allergic reaction that can affect many body systems – upper and lower respiratory, skin, cardiovascular and gastrointestinal. Anaphylaxis is an overreaction of the body’s immune system triggering allergen (the substance you are allergic to). It usually occurs soon after exposure, and can be mild to life-threatening. It may subside quickly with treatment, require more than one dose of epinephrine to manage, or reoccur, usually 1 to 8 hours later.
Anaphylaxis requires immediate attention and treatment.
How common is anaphylaxis?
It is estimated that 2% of the population (approximately 600,000 Canadians) are at risk for severe allergic reactions. The rate of anaphylaxis may be higher in children, and has increased dramatically over the last 10 years. Although usually diagnosed in childhood, it can begin later in life.
How do I know if I am having a serious reaction?
If several symptoms occur at the same time, immediate treatment is required. Symptoms may begin within minutes to several hours after exposure to triggering allergen(s) and can intensify to become life threatening.
Never ignore symptoms of anaphylaxis, no matter how mild.
One anaphylactic episode that is reversed with treatment is called a uniphasic reaction. If symptoms return after the person feels better, occasional up to 24 hours after the first reaction, it is called a biphasic reaction. Roughly 20% of anaphylactic reactions will be biphasic in nature. Approximately 60% of biphasic reactions are as severe or can be even worse than the initial reaction.
It is important to know that the severity of previous anaphylactic reactions do not determine the severity of future reactions, and subsequent reactions could be the same, better, or worse. The severity depends on the degree of allergy and the dose of allergen, not what you have experienced before.