Allergies and/or 'hypersensitivities' are overreactions of the
immune system.
These overreactions are particular to substances in some
people. There are four groups of Hypersensitivities.
The classifications
are based on what parts of the immune system are activated, as well as
how long it takes for a reaction to occur. In type I hypersensitivity, a
particular foreign substance, 'allergen', and reacts with a specific
type of antibody called immunoglobulin E - this reaction causes symptoms
that will appear within minutes. In type IV hypersensitivity, the
allergen reacts with a specialized type of cell called a T-lymphocyte.
The reaction time of type IV is quite long it hours or days until any
symptoms appear.
Type I allergic reactions can be inconstant in
severity, it might appear different from time to time, causing a rash
the first time and anaphylaxis the next. Type I allergies can be related
to just about anything: foods, plants, insect venoms, animal dander,
dust mites, mould spores, occupational substances (for example latex),
as well as drugs and penicillin. There can also be cross-reactions,
where someone allergic to grass pollen, for instance, may also react to
melons and tomatoes. The most common food-related causes of severe
anaphylactic reactions are peanuts, tree nuts, and shellfish.
Type
IV delayed hypersensitivity reactions are most often skin reactions.
Common examples include reactions to metal and jewelry. They occur when
an allergen interacts with specific T lymphocytes. Type IV
hypersensitivity is usually a reaction (redness, swelling, hardening of
the skin, rash, dermatitis) observed at the exposure site hours to days
after exposure.
Type I acute allergic reaction can cause a rash,
dermatitis, and itching, while in the long term the allergy may cause
atopic dermatitis and eczema. In the respiratory tract, the acute
reaction causes coughing, nasal congestion, sneezing, throat tightness.
This can in long term led to asthma. It can also cause red itchy eyes.
Acute allergic reactions in the gastrointestinal system start in the
mouth with swelling of the tongue and throat, followed by abdominal
pain, muscle spasms, vomiting and diarrhea.
Any severe acute
allergic reaction can be potentially life threatening, causing
anaphylaxis, a reaction spread throughout the entire body that can start
with agitation, a 'feeling of impending doom' pale skin (due to low
blood pressure), and/or loss of consciousness (fainting). Anaphylaxis
can be fatal without the rapid administration of an adrenaline or
cortisone injection.
The best treatment for allergy is to be
cautious and keep away from the substances that trigger your allergy.
Allergies are unpredictable and might go away after a couple of years
but they might as well stay with you forever.
If you fear an allergy it is of high importance to take a test and determine what substances you are hypersensitive to.
Adapted from EzineArticles.com/8336445
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