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Anaphylaxis (The Most Serious Allergic Reaction)


Anaphylaxis is the most severe allergic reaction and is potentially life threatening.
Anaphylaxis is rare. The vast majority of people will never have an anaphylactic reaction.
The most common causes of anaphylaxis include drugs, such as penicillin, insect stings, foods, x-ray dye, latex, and exercise.
The symptoms of anaphylaxis may vary from hives, tongue swelling, and vomiting, to shock.
If you are at risk, avoidance is the best form of treatment.
Always carry an epinephrine kit with you since it could save your life.

Anaphylaxis refers to a rapidly developing and serious allergic reaction that affects a number of different areas of the body at one time. Severe anaphylactic reactions can be fatal. Most people experience allergy symptoms only as a minor annoyance. However, a small number of allergic people are susceptible to a reaction that can lead to shock or even death. Fortunately, anaphylaxis is rare. The death rate from anaphylaxis is about 1 out of every 2.5 million people per year.

Anaphylaxis is often triggered by substances that are injected or ingested and thereby gain access into the blood stream. An explosive reaction involving the skin, lungs, nose, throat, and gastrointestinal tract can then result. Although severe cases of anaphylaxis can occur within seconds or minutes of exposure and be fatal if untreated, many reactions are milder and can be ended with prompt medical therapy.

What Does Anaphylaxis Mean?

To fully understand this term, we need to go back almost 100 years. The story begins on a cruise aboard Prince Albert I of Monaco’s yacht. The Prince had invited two Parisian scientists to perform studies on the toxin produced by the tentacles of a local jellyfish, the Portuguese Man of War. Charles Richet and Paul Portier were able to isolate the toxin and tried to vaccinate dogs in the hope of obtaining protection, or “prophylaxis,” against the toxin. They were horrified to find that subsequent very small doses of the toxin unexpectedly resulted in a new dramatic illness that involved the rapid onset of breathing difficulty and resulted in death within 30 minutes. Richet and Portier termed this “anaphylaxis” or “against protection.” They rightly concluded that the immune system first becomes sensitized to the allergen over several weeks and upon re-exposure to the same allergen may result in a severe reaction. You will recall that an allergen is a substance that is foreign to the body and can cause an allergic reaction in certain people. These are concepts with which you are now familiar from our previous allergy chapters.

Allergy Facts
The first documented case of presumed anaphylaxis occurred in 2641 B.C. when Menes, an Egyptian pharaoh, died mysteriously following a wasp or hornet sting. Later, in Babylonian times, there are two distinct references to deaths due to wasp stings.
Charles Richet was awarded the Nobel Prize in 1913 for his work on anaphylaxis.
Richet went on to suggest that the allergen must result in the production of a substance, which then sensitized the dogs to react in such a way upon re-exposure. This substance turned out to be IgE. He was right on target.

In the first part of the 20th century, anaphylactic reactions were most commonly caused by tetanus diphtheria vaccinations made from horse serum. Today, human serum is used for tetanus prevention and the most common causes of anaphylaxis are now penicillin and other antibiotics, insect stings, and certain foods.

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