Tips to Remember:
Anaphylaxis is a severe allergic reaction
that may involve the entire body. It can result in trouble breathing, loss
of consciousness and even death. Anaphylaxis is a medical emergency that
requires immediate medical treatment, and later follow up care by an
Anaphylaxis can occur in some people after
they are exposed to a substance to which they are severely allergic. The
most common substances that trigger anaphylaxis are foods, medications, and
insect stings. It has been estimated that up to 15% of the population is at
risk for anaphylaxis.
Anaphylaxis is triggered the same way other allergies are: the immune system
- which serves as the body's defense against potentially dangerous
substances such as germs - overreacts to a harmless substance (an
allergen) and in that process can damage the body. As part of the normal
immune response, proteins called antibodies are produced that can
detect and help destroy "invaders" in the body. A specific antibody called
Immunoglobulin E, or IgE, is responsible for the adverse
reactions in people with allergies.
When allergens first enter the body of a
person predisposed to allergies, the immune system produces the
allergen-specific IgE antibodies. The IgE antibodies attach themselves to
the surface of cells called mast cells. The next time that allergic
individual comes into contact with the allergen, the IgE identifies it and
quickly initiates the release of chemicals - such as histamine - from the
mast cells. These potent chemicals cause the symptoms seen in allergic
reactions and anaphylaxis.
Some individuals experience severe allergic
reactions due to the release of the same potent chemicals, but without IgE
antibodies being involved. These are called anaphylactoid reactions
and triggers include certain pain medications - e.g., non-steroidal,
anti-inflammatory drugs(NSAIDS) such as aspirin or ibuprofen or narcotic
medications - and injected dye used for radiographic studies.
Symptoms of anaphylaxis
Anaphylaxis is a "systemic reaction," which means that various parts of the
body are affected that are a distance from the allergen's initial entry site
(e.g., a sting site for insects or the stomach for foods). Symptoms of
anaphylaxis can vary from mild to severe and are potentially deadly. Here is
a list of possible symptoms that may occur alone or in any combination:
Skin: hives, swelling, itch, warmth,
Breathing: wheezing, shortness of breath, throat tightness, cough,
hoarse voice, chest pain/tightness, nasal congestion/hay fever-like
symptoms, trouble swallowing
Stomach: nausea, pain/cramps, vomiting, diarrhea, itchy
Circulation: pale/blue color, poor pulse, passing-out,
dizzy/lightheaded, low blood pressure, shock
Other: anxiety, feeling of "impending doom," itchy/watery eyes,
headache, cramping of the uterus, itchy/red eyes
Reactions usually begin within minutes of
exposure, but may be delayed. Sometimes symptoms resolve, only to recur or
progress a few hours later. The most dangerous symptoms are low blood
pressure, breathing difficulties, shock and loss of consciousness, all of
which can be fatal.
There are a variety of medical conditions
that may mimic anaphylaxis. These include heart attacks, anxiety attacks,
choking and seizures, among others. If you experience any unusual symptoms,
it is vitally important to seek immediate medical attention (e.g., call 911)
for prompt treatment and to determine the cause of the symptoms.
Substances that trigger reactions
Foods: Essentially any food can
trigger an allergic reaction, but some of the most common ones that cause
severe anaphylaxis are: peanuts, nuts from trees (e.g., walnut, cashew,
Brazil nut), shellfish, fish, milk and eggs. Food additives such as
sulfites can also sometimes trigger anaphylactoid reactions.
Stinging insects: The venom of stinging insects such as yellow
jackets, honeybees, paper wasps, hornets and fire ants cause discomfort
for most people who are stung. However, reactions can be severe and even
deadly for people with allergies to these venoms.
Medications: Virtually any medication can trigger an allergic
reaction. Common categories of drugs that cause anaphylaxis are
antibiotics and anti-seizure medicines. Medical therapies such as certain
post-surgery fluids, vaccines, blood and blood products, radiocontrast
dyes, pain medications and other drugs may cause anaphylaxis or
Latex: Some products made from natural latex (from the rubber tree)
contain allergens that can trigger reactions in sensitive individuals. The
greatest danger of severe reactions occurs when latex comes into contact
with moist areas of the body or internal surfaces during surgery, because
more of the allergen can rapidly be absorbed into the body.
Exercise: Although rare, exercise can also trigger anaphylaxis.
Oddly enough, it does not occur after every exercise session and in some
cases, only occurs after eating certain foods before exercise.
Other: Anaphylaxis has rarely been associated with exposure to
seminal fluid, hormones and exposure to extreme temperatures. When no
cause is found and the reaction is definitely anaphylaxis, it is termed
Treatment and prevention
If you (or anyone you are with) begins experiencing severe allergy symptoms,
call for medical help to get to an emergency room, where you may receive an
epinephrine (adrenalin) shot to relieve breathing problems and improve
circulation, and other medications such as antihistamines (that reduce the
swelling and itch) or steroids (that further reduce the allergic response).
The sooner the reaction is treated, the less severe it is likely to become.
Even if you have received immediate medical treatment on site, you should be
transported to a hospital for further evaluation.
If you have ever had anaphylaxis, make sure
to see an allergist/immunologist for follow-up evaluation and treatment. The
allergist/immunologist will take your medical history and conduct other
tests, if needed, to determine the exact cause. Once the trigger of the
reaction is identified, your allergist/immunologist can provide detailed
information about avoiding the substance, and possibly related ones, that
poses danger. Avoidance of the allergen(s) is the primary way to remain
safe, but requires quite a great deal of education. Specific advice may
Food: how to interpret ingredient
labels, manage restaurant dining, avoid food cross-contact
Insects: reducing perfumes, bright color clothing, and "high risk"
activities, wear long sleeves/pants
Medications: which drugs/treatments to avoid, a list of alternative
medications that should be tolerated
In some cases, your allergist/immunologist
may suggest specific treatments. For example, vaccines ("allergy shots") to
virtually eliminate the risk of anaphylaxis from insect stings are
available, and there are procedures that make it possible to be treated with
certain medications to which you are allergic.
Your allergist/immunologist may also
prescribe a self-injectable epinephrine shot to carry with you. This
medication reverses the allergic reaction, at least temporarily, to provide
the life-saving time needed to get further treatment in a medical facility.
Learn how to self-administer the epinephrine according to your
allergist/immunologist's instructions, and replace the device before the
labeled expiration date.
You may also want to wear a special bracelet
or necklace that identifies you as having a severe allergy. These tags can
also supply other important information about your medical condition.
If you have had an anaphylactic reaction, you
may want to inform family, health care workers, employers and school
personnel about your allergy so they can watch for symptoms and help you
avoid your allergy triggers. Above all, make sure to work in partnership
with your allergist/immunologist to ensure your safety and health.
What your allergist/immunologist can do
- Determine if you have had, or are at risk for, anaphylaxis
- Determine what trigger(s) may cause your reaction
- Teach you how to avoid the allergen(s)
- Provide education about recognizing symptoms of an allergic reaction
- Create an emergency treatment plan for use by you and others
- Offer the most up-to-date therapies to treat and/or prevent reactions
Your allergist/immunologist can provide
you with more information on anaphylaxis.
Tips to Remember are created by the
Public Education Committee of the American Academy of Allergy, Asthma and
Immunology. This brochure was updated in 2003.
The content of this brochure is for
informational purposes only. It is not intended to replace evaluation by a
physician. If you have questions or medical concerns, please contact your
American Academy of Allergy,
Asthma and Immunology
555 East Wells Street
Milwaukee, WI 53202-3823
Physician Referral and
AAAAI Web site