Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.
Anaphylaxis is a severe allergic reaction that occurs rapidly and causes a life-threatening response involving the whole body. This reaction can lead to difficulty breathing and shock ultimately leading to death.
For an anaphylactic reaction to occur, you must have been exposed in the past to the substance that causes the reaction, called the antigen. This is called "sensitization."
A bee sting, for example, may not cause an allergic reaction the first time.
Another bee sting may produce a sudden, severe allergic reaction known as anaphylaxis or anaphylactic shock.
These reactions usually occur within seconds to minutes of exposure. Occasionally, they are delayed.
You may develop sensitivity and anaphylaxis to a substance that you have been exposed to many times in the past without a reaction, and often people don't recall the previous exposure.