What is allergy?
Allergy is a physiological reaction that occurs when
the immune system mistakenly identifies a normally harmless
substance as damaging to the body.
Normally, the human body defends itself against harmful
substances such as viruses or bacteria, but, sometimes,
the defenses aggressively attack usually innocuous substances
such as dust, mold, or pollen.
The immune system generates large amounts of the antibodies
called immunoglobin E(IgE), a complex chemical weapon,
to attack and destroy the supposed enemy. Each IgE antibody
specifically targets a particular allergen the substance
that causes the allergy. In this disease-fighting process,
inflammatory chemicals such as histamines, cytokines,
and leukotrienes are released or produced, and some
unpleasant, and, in extreme cases, life-threatening,
symptoms may be experienced by an allergy-prone person.
What are allergic reactions?
An allergic reaction may occur anywhere in the body
in the skin, eyes, lining of the stomach, nose, sinuses,
throat, and lungs laces where immune system cells are
located to fight off invaders that are inhaled, swallowed,
or come in contact with the skin. Reactions may result
in the following:
What causes allergic reactions?
- rhinitis - nasal stuffiness, sneezing, nasal
itching, nasal discharge, itching in ears or roof
- allergic conjunctivitis - red, itchy, watery
- atopic dermatitis - red, itchy, dry skin.
- urticaria - hives or itchy welts.
- contact dermatitis - itchy rash.
- asthma - airway problems such as shortness
of breath, coughing, wheezing.
Although hundreds of ordinary substances may trigger
allergic reactions, the most common triggers, called
allergens, include the following:
Who is affected by allergy?
- household dust, dust mites and their waste
- animal protein (dander, urine, oil from skin)
- industrial chemicals
- insect stings
- cockroaches and their waste
Allergies can affect anyone, regardless of age, gender,
race, or socioeconomic status. Generally, allergies
are more common in children, however, a first-time occurrence
can happen at any age, or recur after many years of
There is a tendency for allergies to occur in families,
although the exact genetic factors that cause it are
not yet understood. In susceptible people, factors such
as hormones, stress, smoke, perfume, or other environmental
irritants may also play a role. Often, the symptoms
of allergies develop gradually over a period of time.
Allergy sufferers may become so accustomed to chronic
symptoms such as sneezing, nasal congestion, or wheezing,
that they do not consider their symptoms to be unusual.
Yet, with the help of an allergist, these symptoms can
usually be prevented or controlled and quality of life
How is allergy diagnosed?
In addition to a complete medical history and physical
examination, your child's physician may use the following:
Treatment for allergy:
- skin test-a method of measuring the child's level
of IgE antibodies to specific allergens. Using diluted
solutions of these allergens, the physician either
injects your child with the solutions, or applies
them to a small scratch or puncture. Reactions appear
as small red areas on the skin. A reaction to the
skin test does not always mean that your child is
actually allergic to the allergen that caused the
- blood test-used to measure the child's level
of IgE antibodies to specific allergens. One common
blood test is called RAST (radioallergosorbent test).
Specific treatment for allergy will be determined by your
child's physician based on the following:
- your child's age, overall health, and medical history
- extent of the disease
- your child's tolerance for specific medications,
procedures, or therapies
- expectations for the course of the disease
- your opinion or preference