An
allergy
is
an
immune
system
response
to
something
which
is
not
directly
dangerous
to
the
body.
The
term
was
coined
by
Viennese
paediatrician
Baron
Clemens
von
Pirquet
in
1906,
from
the
Greek
words
allos
meaning
changed
or
altered
state
and
ergon
meaning
reaction
or
reactivity.
He
observed
the
exaggerated
immune
responses
of
some
of
his
patients,
and
concluded
that
they
were
a
response
to
outside
allergens
such
as
dust,
pollen,
or
certain
foods.
The
most
basic
allergy
symptoms
are
similar
to
those
of
a
common
cold
-
snuffling,
itchy
eyes,
and
sneezing.
An
allergy
can
also
cause
skin
rashes,
hives
or
weals
such
as
contact
dermatitis
or
eczema;
these
are
often
caused
in
reaction
to
medications.
Hay
fever
is
one
example
of
a
very
common
minor
allergy
-
large
percentages
of
the
population
suffer
from
hayfever
symptoms
in
response
to
airborne
pollen.
Asthmaticss
are
often
allergic
to
dust
mites.
Most
allergies
are
minor
annoyances,
but
they
are
not
something
to
take
lightly.
An
allergy
can
also
be
extremely
life-threatening
if
it
is
severe,
causing
anaphylactic
shock
and
a
total
shutdown
of
the
airways,
circulation
and
every
function
of
the
body.
Treatment
The
only
known
mainstream
medicine
treatment
for
allergy
is
hyposensibilization.
Other
medication,
such
as
by
antihistamines
and
cortisone,
can
have
the
effect
of
reducing
the
symptoms.
A
number
of
modalities
in
alternative
medicine
can
be
effective
in
the
treatment
of
allergies,
particularly
traditional
Chinese
medicine.
Allergy
causation
Recent
research
has
shed
some
light
on
the
mechanism
by
which
many
allergies
operate,
but
this
is
by
no
means
the
whole
story;
some
causative
factors
and
allergenic
pathways
have
yet
to
be
explained.
One
common
mechanism
seems
to
be
that
insufficient
stimulation
of
the
immune
system
at
certain
critical
points
in
the
development
of
the
body
leads
to
a
surfeit
of
"proto-immune"
cells
which
have
not
been
activated
by
the
presence
of
genuine
invasive
pathogens
to
become
true
antibodies.
Once
past
puberty,
the
immune
system
becomes
"fixed",
with
the
majority
of
activated
antibodies
established
such
that
everyday
pathogens
provoke
no
response.
However
the
unactivated
ones
remain,
waiting
for
a
unusual
and
potentially
more
serious
invader.
Minor
irritants,
or
even
the
body's
own
waste
products,
can
then
trigger
an
antibody
reaction
in
these
cells
which
then
incorrectly
become
primed
to
recognise
these
minor
irritants
as
major
invaders.
A
further
exposure
to
these
irritants
then
provoke
a
substantial
and
unwarranted
immune
response
from
the
incorrectly
programmed
antibodies.
It
is
the
symptoms
of
this
exaggerated
response
that
is
seen
as
the
allergic
reaction.
Many
common
allergies
such
as
asthma
have
seen
huge
increases
in
the
years
since
the
second
world
war,
and
many
studies
appear
to
show
a
correlation
between
this
and
our
increasingly
affluent
and
therefore
clean
lifestyles
in
the
west.
This
is
supported
by
studies
in
less
developed
countries
that
do
not
enjoy
western
levels
of
cleanliness,
and
similarly
do
not
show
western
levels
of
incidences
of
asthma
and
other
allergies.
During
this
same
period,
air
quality,
at
one
time
considered
the
"obvious"
cause
of
asthma,
has
shown
a
considerable
improvement.
This
has
lead
some
researchers
to
conclude
that
it
is
our
"too
clean"
upbringing
that
is
to
blame
for
the
lack
of
immune
system
stimulation
in
early
childhood.
Many
children
have
a
natural
tendency,
for
example,
to
consume
soil
-
a
practice
that
often
provokes
an
equally
natural
tendency
in
parents
to
stop
them.
However,
it
appears
that
this
may
have
a
valuable
function
in
priming
the
immune
system,
and
is
one
way
to
ensure
that
allergies
are
less
likely
to
develop
in
later
life.
Another
theory
is
the
exponential
use
and
abuse
of
chemicals
in
affluent
nations
since
the
second
world
war.
Vast
numbers
of
chemicals
are
introduced
into
our
indoor
and
outdoor
environments
with
little
or
no
testing
regarding
their
toxicity
to
living
beings.
Many
believe
that
air
quality
is
getting
worse
rather
than
better,
particularly
if
one
considers
indoor
air
quality
as
well
as
outdoor.
Adverse
reactions
to
toxins
vary
considerably
from
one
person
to
another,
and
can
involve
extremes
in
symptoms
involving
the
neurological
system
as
well
as
more
typical
allergy
symptoms
listed
above.