Introduction
Anaphylaxis is a Type I hypersensitivity Reaction. This is an acute reaction to a trigger allergen to which a patient has been exposed and is sensitized. The Type I reaction is an Immunoglobulin E mediated reaction, causing degranulation of mast cells. The physiologic mediators released by mast cells vary by anatomic site. They may act on smooth muscle, vascular system, mucosal glands, platelets, eosinophils or on peripheral sensory nerves.
Some typical allergens are contained in
- Foods - such as nuts, seafood, eggs, and milk
- Insect - stings such as bee, ant or wasp venom, or dust mites
- Plant pollens - ragweed and rye grass
- Medications - vaccines, antibiotics, anesthetics
In the US, penicillin is the leading cause of fatality due to anaphylaxis. Over 5000 deaths are attributable to penicillin, the cause of 75% of deaths due to anaphylactic shock. Upto 27 million people in the US are allergic to it.
Rapid treatment (within minutes) with epinephrine is a proven lifesaver. EpiPen® is an example of a product that should carried by at risk people at all times. It is an auto-injector that facilitates a person self administering epinephrine.