Allergies in Children

What are allergies in
children?

Allergies are problems of the immune system. Most allergic reactions happen when the
immune system reacts to a “false alarm.” Normally, the human body defends itself against
harmful things such as viruses or bacteria. But sometimes the defenses violently attack
mostly mild things, such as dust, mold, or pollen.

Normally, allergens are harmless. But when a person has allergies, the body thinks
these allergens are harmful. The body then attacks allergens with antibodies called
immunoglobulin E (IgE). These antibodies are attached to special cells called mast
cells. Allergens stick to the antibodies. This makes the mast cells release histamine
and other chemicals causing an allergic reaction. When the chemicals irritate nearby
nasal tissue, this causes nasal allergy symptoms. When this happens in the lungs’
breathing tubes, it can cause asthma symptoms such as cough and wheeze. When the
reaction involves the whole body, this can be a severe allergic reaction.

What causes allergies in a
child?

Many
things can trigger allergic reactions. But the most common triggers or allergens
are:

  • Tree,
    grass, and weed pollens
  • Natural
    rubber latex
  • Molds
  • Dust
    mites
  • Animal
    dander, urine, and oil from skin
  • Foods
  • Medicines
  • Feathers
  • Bee
    stings
  • Pests
    such as cockroaches and mice

Which children are at risk for
allergies?

Allergies can affect anyone. It doesn’t matter regardless of age, gender, race, or
socioeconomic status. Generally, allergies are more common in children. But allergies
can happen at any age. And they can come back after being in remission for many
years.

Allergies tend to happen in families. But the exact reason isn’t yet understood.
Allergy symptoms often happen slowly over time.

What are the symptoms of allergies
in a child?

An
allergic reaction can happen anywhere in the body. This includes the skin, eyes, lining
of the stomach, nose, sinuses, throat, and lungs. These are the places where immune
system cells are found to fight off germs that are breathed in, swallowed, or come in
contact with the skin. Allergic reactions can cause:

  • Stuffy
    nose, sneezing, itching, or runny nose, and itching in ears or roof of mouth
  • Red,
    itchy, watery eyes
  • Red,
    itchy, dry skin
  • Hives or
    itchy welts
  • Itchy
    rash
  • Asthma
    symptoms, such as shortness of breath, coughing, wheezing
  • A
    severe, life-threatening allergic reaction (anaphylaxis). This can cause trouble
    breathing, vomiting, diarrhea, low blood pressure, fainting, or death.

How are allergies diagnosed in a
child?

To
diagnose an allergy, the healthcare provider will take a complete health history and
examine your child. The provider may also do these tests:

  • Skin test.
    This is the most common allergy test. Skin tests measure if there are IgE
    antibodies to certain allergens (like foods, pollens, or animal dander). A small
    amount of diluted allergen is placed on the skin. The area is pricked or scratched.
    If a person is allergic to the allergen, a small raised bump (like a mosquito bite)
    appears after about 15 minutes. Testing for many allergens may be done at the same
    time. An allergist may also do an intradermal test. In this test, a small amount of
    allergen is injected just under the skin. This type of skin testing is more sensitive
    than prick or scratch testing. Skin test results are available right after the
    testing is done.
  • Blood test.
    Blood tests for allergies measure IgE antibodies to certain allergens in the
    blood. The testing that is most often used is called RAST (radioallergosorbent test).
    Blood tests may be used when skin tests can’t be done. For example, in people with
    certain skin conditions. Or people with a very recent severe allergic reaction. A
    positive blood test does not always mean that you have a certain allergy. Any
    positive blood test needs to be interpreted by a healthcare provider who is familiar
    with the tests and knows your child’s health history. These tests take longer to get
    results. They may cost more than other allergy tests.
  • Challenge test. This test is supervised by an allergist. A very small amount
    of the allergen is given to the child by mouth. Or it is breathed in. Only a
    challenge test can figure out how severe an allergy is. Skin or blood test reactions
    only tell the likelihood of having any type of reaction, not what that reaction will
    be.

Any positive test needs to be explained by a healthcare provider who
is familiar with the test and your child’s health history.