LESSON 3
ANAPHYLAXIS AND ANAPHYLACTIC SHOCK
3-1.
INTRODUCTION
When a foreign protein or other foreign substance is introduced into the body, the
normal systemic reaction is to throw off the substance. Anaphylaxis is an unusual
allergic reaction. It is caused by a hypersensitivity to a specific substance introduced
into the body for the second or a subsequent time. Anaphylaxis is never apparent
during the first contact with the foreign substance. During the time between the first and
second experience with the foreign substance, the person develops antibodies. In a
majority of cases, the antibody produced is immunoglobin IgE. When the foreign
substance (antigen) makes later contact with the person, there is an antigen-antibody
reaction. The body releases a toxic histamine-like substance that causes a mild to
lethal reaction. When the reaction is severe, it is called anaphylactic shock. The
shorter the time before symptoms appear, the greater the risk of a fatal reaction.
Anaphylactic shock is always considered a serious medical emergency.
3-2.
SUBSTANCES CAUSING ANAPHYLACTIC SHOCK
a. There are many kinds of substances that can produce anaphylactic shock.
These substances may be absorbed from injections, ingestion or inhaling them.
(1) Injections of serums or drugs. Parenteral injections of penicillin are the
most frequent cause of anaphylactic shock. If the drug is ingested, the reaction is less
rapid than through injection, but will still occur. Tetanus antitoxin is another frequent
cause. Some antitoxins and extracts of allergenic substances are formed by using
animal serum. When these are used for testing or desensitizing an allergic patient,
these can cause anaphylactic shock. Diagnostic medical procedures such as an
angiogram or pyelogram use contrast media containing iodide. These media have been
known to produce a serious allergic response.
(2) Insect stings. When sudden death results from a bee sting, this is due to
anaphylactic shock. Wasps, hornets, yellow jackets, and other stinging insects are also
possible causes.
(3) Foods. Shellfish is a frequent cause of anaphylactic shock. Other
culprits include other types of fish, milk, and strawberries. Other types of berries can
also cause this reaction.
(4) Drugs. Several kinds of ingested drugs can be causes. There have
been cases of deaths caused by acetylsalicylic acid (aspirin) as it was absorbed into the
blood stream. This drug is not as safe as it was once believed.
MD0588
3-2