- What is Anaphylaxis?
- Who gets Anaphylaxis?
- Predisposing Factors
- Probable Outcomes
- How is Anaphylaxis Diagnosed?
- How is Anaphylaxis treated?
- Anaphylaxis References
- Drugs/Products Associated with Anaphylaxis
What is Anaphylaxis?
Anaphylaxis is a sudden, severe allergic reaction to a substance (called an allergen) that can be life-threatening. Common substances which can cause as severe allergic reaction include bee stings, insect bites, peanuts, eggs, drugs given to the body, etc. Anaphylaxis suddenly affects the whole body, with severe allergic symptoms including: difficulty breathing, rash, swelling, tummy pain, and reduced blood pressure leading to shock. Anaphylaxis is a medical emergency where immediate treatment is needed to prevent potential death. When exposed to a foreign substance, some people suffer reactions identical to anaphylaxis, but in which no allergy is involved. These reactions are called anaphylactoid, meaning anaphylaxis-like reactions. In anaphylaxis, the immune system must be "primed" by previous allergen exposure. But in anaphylactoid reactions can occur with no previous allergen exposure at all. An example of something that can bring on a severe allergic reaction is radiographic contrast material (the dye injected into arteries and veins to make them show up on an x-ray). Although the mechanism of an anaphylactoid reaction is different. The allergy treatment is the same.
Who gets Anaphylaxis?
Anaphylaxis occurs infrequently. However, it is life-threatening and can occur at any time. Milder forms of anaphylaxis occur much more frequently than fatal anaphylaxis. The frequency of anaphylaxis is increasing and this has been attributed to the increasing number of potential allergens to which people are exposed. In the US, anaphylaxis causes approximately 500-1000 deaths in a year. However the figure is difficult to determine accurately because of underdiagnosis and underreporting. No major differences have been reported in the incidence and prevalence of severe allergic reactions between men and women. Anaphylaxis occurs in all age groups. While prior exposure to allergens is essential for the development of true anaphylaxis, severe allergic reactions occur even when no documented prior exposure exists. Thus, patients may react to a first exposure to an antibiotic or insect sting. Adults are exposed to more potential allergens than are pediatric patients. The elderly have the greatest risk of mortality from severe allergic reactions due to the presence of other diseases usually suffered by elderly population.
The likelihood of an individual having anaphylaxis is influenced by the following:
The signs and symptoms of anaphylaxis may occur almost immediately after exposure or within the first 20 minutes after exposure. Rapid onset and development of potentially life threatening symptoms are characteristic markers of anaphylaxis.
may initially appear mild or moderate but can progress rapidly. The most dangerous allergic reactions involve the lungs and/or heart/vessel system.
|Created: 26/6/2005||Modified: 2/7/2009|