Allergy Basics

What Are Allergies?

Allergies are an overreaction of the immune system. People who have allergies
have a hyper­alert immune system that overreacts to a substance in the
environment called an allergen. Exposure to what is normally a harmless
substance, such as pollen, causes the immune system to react as if the
substance is harmful.
Allergies are a very common problem, affecting at least 2 out of every 10
Americans.
What Happens During an Allergic Reaction?
When a person with a hyper­alert immune system is exposed to an allergen, a
series of events takes place:

1. The body starts to produce a specific type of antibody, called IgE, to fight
the allergen.

2. The antibodies attach to a form of blood cell called a mast cell. Mast cells
are plentiful in the airways, and in the GI tract where allergens tend to
enter the body.

3. The mast cells explode releasing a variety of chemicals including
histamine, which causes most of the symptoms of an allergy, including
itchiness or runny nose.

If the allergen is in the air, the allergic reaction will occur in the eyes, nose, and
lungs. If the allergen is ingested, the allergic reaction will occur in the mouth,
stomach, and intestines. Sometimes enough chemicals are released from the
mast cells to cause a reaction throughout the body, such as hives decreased
blood pressure, shock, or loss of consciousness. This severe type of reaction is
called anaphylaxis and can be life­threatening
What Are the Symptoms of Allergies?
Allergy symptoms can be categorized as mild, moderate, or severe
(anaphylactic).
· Mild reactions include those symptoms that affect a specific area of the
body such as a rash or hives, itchy, watery eyes, and some congestion.
Mild reactions do not spread to other parts of the body.
· Moderate reactions include symptoms that spread to other parts of the
body. These may include itchiness or difficulty breathing.· A severe reaction, called anaphylaxis, is a rare, life­threatening emergency in which the body's response to the allergen is sudden and
affects the whole body. It may begin with the sudden onset of itching of
the eyes or face and within minutes progress to more serious symptoms,
including varying degrees of swellings that can make breathing and
swallowing difficult, abdominal pain, cramps, vomiting, and diarrhea.
Mental confusion or dizziness may also be symptoms, since anaphylaxis
causes a quick drop in blood pressure.

Does Everyone Have Allergies?

No. Most allergies are inherited, which means they are passed on to children
by their parents. People inherit a tendency to be allergic, although not to any
specific allergen. When one parent is allergic, their child has a 50% chance of
having allergies. That risk jumps to 75% if both parents have allergies.
Allergy Triggers
There are a number of different allergy­causing substances. The most common
include pollen, dust mites, mold, animal dander, insect stings, latex, and certain
food and medication. If you have an allergy your symptoms can range from mild
eye irritation and congestion to a more severe reaction causing swelling and
difficulty breathing. And, if you have asthma, a reaction to any offending allergy­
causing substance can worsen your asthma symptoms. But, there are steps you
can take to prevent and treat allergy attacks when they occur.

Pollen


Exposure to pollen can trigger hay fever or seasonal allergies. Symptoms include
sneezing, runny nose, nasal congestion, and itchy, watery eyes. Treatments
include over­the­counter and prescription antihistamines such as Benadryl,
Clarinex, or Allegra, decongestants like Sudafed, nasal steroids like Beconase
and Flonase, Nasalcrom and drugs that combine antihistamines and
decongestants like Allegra­D, Claritin­D or Zyrtec. Allergy shots, also called
immunotherapy, are also an option.
Prevent hay fever symptoms by staying indoors when pollen counts are high,
closing windows, and using air conditioning.

Dust Mites


Dust mites are microscopic organisms that live in house dust. House dust is a
mixture of potentially allergenic materials including fibers from different fabrics,
dander from animals, bacteria, mold or fungus spores, food particles, bits of
plants, and others. Symptoms of dust mite allergy are similar to pollen allergy butoften occur year round rather than just seasonally. Treatment may include
medications such as antihistamines or decongestants.
Prevent dust mite allergy by putting plastic covers over mattresses, using
hypoallergenic pillows, washing sheets weekly in hot water and keeping all areas
of the house, especially the bedroom, free of dust collecting stuffed animals,
curtains, and carpet.

Molds


Molds are parasitic, microscopic fungi with spores that float in the air like pollen.
Mold is a common trigger for allergies and can be found in damp areas such as
basements or bathrooms, as well as in grass, leaf piles, hay, mulch, or under
mushrooms. Symptoms of mold allergies can occur seasonally, especially in the
summer and fall or year round if mold is in your home. Symptoms are like those
of pollen and dust mite allergies and include sneezing, congestion, itchy and
watery eyes, runny nose, and coughing. Treatments are the same as those for
dust mites or pollen.
Prevent mold allergies by avoiding activities that trigger symptoms, such as
raking leaves. Keep windows and doors closed, and make sure moist places in
the home, such as the basement and bathrooms, are well ventilated.

Animal Dander and Cockroaches


Proteins secreted by oil glands in an animal's skin, as well as the proteins
present in an animal's saliva, can cause allergic reactions in some people.
Allergies to animals can take two or more years to develop and symptoms may
not subside until months after ending contact with the animal. Symptoms include
sneezing, congestion, and itchy and watery eyes. Treatments include avoiding
exposure to animals that cause your allergies when possible. Medications such
as antihistamines, decongestants, nasal steroids, or others may be helpful.
Immunotherapy may be recommended if your symptoms are chronic.
Cockroaches can cause similar symptoms. The treatments are the same.
Prevent allergies to pet dander and cockroaches by removing the pet from the
home, or at least the bedroom. Keep pets off upholstered furniture, wash the pet
weekly. Cockroach allergy can be prevented by keeping trash in closed
containers and taking it out regularly.

Insect Stings

Everyone who gets stung by an insect will have pain, swelling, and redness
around the sting site. However, people who are allergic to stings can have a
severe or even life­threatening reaction. Symptoms of insect sting allergy includeextensive swelling and redness from the sting or bite that may last a week or
more, nausea, fatigue, and low­grade fever. On rare occasions, insect stings may
cause a full­body allergic reaction called anaphylaxis. Symptoms of anaphylaxis
may include difficulty breathing, hives, swelling of the face, throat or mouth,
wheezing or difficulty swallowing, restlessness and anxiety, rapid pulse,
dizziness, or a sharp drop in blood pressure. For people who are severely
allergic to insect stings, the medicine epinephrine should be administered soon
after being stung to prevent the development of a life­threatening situation.
Prevention is the best treatment. Minimize exposure to insects by not wearing
brightly colored clothes and scented cosmetics and by keeping insecticide
available, wearing shoes outdoors, and avoiding outdoor garbage. If you do get
stung, remove the stinger. If you are at risk of anaphylaxis, get an epinephrine
injection immediately. An oral antihistamine, like Benadryl, may be taken to
reduce itching, swelling, and hives, and a pain­reliever may be taken and ice
pack used to dull pain caused by the sting.
Insects that cause allergic reactions include various bees, fire ants, yellow
jackets, hornets, and wasps.


Latex

Rubber gloves are the most common offending product for people with a latex
allergy, but a latex allergy can also be triggered by latex in condoms and certain
medical devices. Symptoms of latex allergy include skin rash, hives, eye tearing
and irritation, runny nose, sneezing, cough, wheezing, shortness of breath, and
itching of the skin or nose. Allergic reactions to latex can range from skin redness
and itching to a much more serious reaction, called anaphylaxis which can cause
difficulty breathing, hives, or sudden gastrointestinal problems.
Treatments include removal of the latex product. To relieve symptoms,
antihistamines or epinephrine will be given. If you have a latex allergy, it is
important for you to wear a Medic Alert bracelet and carry an emergency
epinephrine kit at all times. To prevent a latex reaction, sensitive individuals
should avoid products containing latex.

Foods

Milk, fish and shellfish, nuts, wheat, and eggs are the most common foods that
cause allergies. A food allergic reaction usually occurs within minutes of eating
the offending food and symptoms, which can include asthma, hives, runny nose,
vomiting, diarrhea, and swelling in the area around the mouth, can be severe.
The best treatment is to avoid the offending food altogether; but when exposed,
treatment with antihistamines or steroids is recommended. In life­threatening
situations, an epinephrine injection is needed to reverse symptoms.Medication
Some people develop allergies to certain medications, such as penicillin or
aspirin. Symptoms can range from mild to life­threatening and can include hives,
skin rash, itchy skin or eyes, congestion, and swelling in the mouth and throat.
The best treatment of drug allergies is to avoid the offending drug altogether;
however, when exposed, treatment with antihistamines or steroids is
recommended. For coughing and lung congestion, drugs called bronchodilators
may be prescribed to widen the airways. For more serious symptoms
epinephrine may be needed.
Allergy symptoms can be categorized as mild, moderate, or severe.
Mild Allergic Reactions

Can include:
·  Rash or hives
·  Itchy, watery eyes
·  Congestion

Mild reactions do not spread to other parts of the body.
Moderate Allergic Reactions
Can include symptoms that spread to other parts of the body, including:
·  Itchiness
·  Difficulty breathing
Severe Allergic Reactions (Anaphylaxis)
Anaphylaxis is a rare, life threatening emergency in which the body’s response to
the allergen is sudden and affects the whole body. It may begin with sudden
itching of the eyes or face and within minutes progress to more serious
symptoms, including:
·  Varying degrees of swelling that can make breathing and swallowing
difficult
·  Abdominal pain
·  Cramps
·  Vomiting
·  Diarrhea
·  Mental confusion or dizziness