Anaphylaxis
What is
it?
Anaphylaxis
is a life-threatening allergic reaction to a substance
that is normally harmless to most people.
Who gets
it?
Anyone can
suffer allergic reactions, but anaphylaxis occurs in
people with an extreme sensitivity to a certain
substance.
What
causes it?
An allergic
reaction occurs when the immune system produces
antibodies and other disease fighting cells in
response to an allergen. An allergen is a substance,
most often an insect sting, drug, or food, that causes
an allergic response. The antibodies release chemicals
that actually injure the surrounding cells and cause
the physical symptoms of an allergic reaction. Certain
antibodies release histamines, which affect the skin,
mucous membrane, mucous gland, and smooth muscle
cells. Life-threatening allergic reactions can occur
without any previous symptoms of allergy. Exercise or
exposure to cold can trigger anaphylaxis in some
people.
What are
the symptoms?
Symptoms of
anaphylaxis occur quickly and progress rapidly. They
can include sudden anxiety and weakness, itching,
swelling, hives, cramps, diarrhea, vomiting,
difficulty breathing, tightness in the chest, very low
blood pressure, loss of consciousness, and shock.
Anaphylactic shock can occur within minutes and result
in death. A patient in anaphylactic shock needs
immediate medical treatment.
How is it
diagnosed?
Anaphylaxis
is diagnosed based upon its rapidly progressing
symptoms. Your doctor may order blood and skin tests
to identify specific allergens.
What is
the treatment?
People who
have anaphylactic reactions should, of course, avoid
the allergens that trigger this response. Anaphylactic
shock is treated with an injection of epinephrine, a
hormone that stimulates the heart and relaxes the
airways. This may be combined with an injection of an
antihistamine, which counteracts the histamine
produced by the immune cells during an allergic
reaction. Those who are known to have severe allergies
should carry a self-injection kit, including
antihistamine tablets, for emergency treatment.
However, they should still seek medical care after any
type of anaphylactic reaction. Patients with
anaphylactic reactions may need to receive
supplementary oxygen and intravenous (IV) fluids. In
severe cases, a breathing tube may need to be inserted
to open the airways. People who are severely allergic
may undergo a desensitization program, in which a
series of injections of the allergen are given in
increasingly larger doses until the body shows that it
can be tolerated. This type of program must be
administered by an allergy specialist and it may take
anywhere from 15 to 20 weeks to develop an immunity.
These are followed up with monthly booster shots.
Self-care
tips
The only
way to prevent anaphylaxis is to avoid known
allergens. Some of the most common include bee stings,
fish and shellfish, penicillin, latex, certain
vaccines, nuts and seeds, and certain food additives.
If you have a history of anaphylaxis, you should wear
a medical ID bracelet containing information on your
allergies.
This information has been designed as a comprehensive and quick reference
guide written by our health care reviewers. The health information written
by our authors is intended to be a supplement to the care provided by your
physician. It is not intended nor implied to be a substitute for
professional medical advice.
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