Question:
I'm just doing a little investigating about why adults suddenly
develop allergies, and in particular, why would someone become allergic
to a medication like tylenol later in life after having no prior allergy
to tylenol? My mother developed an allergy to tylenol and then to other
things, which then developed into accute asthma. Has anyone come across some possible reasons for adults (middle-aged) to
develop these allergies? Body chemistry changes? Some outside
influence? I mention outside influence because my mother is a nurse and
it seemed like some time after she had vaccinations (hepatitis...) for
her job she developed these strange allgeries she never had before. I
am just guessing here since I'm just starting to look into this.
Answer:
Allergies are considered to be genetic in origin. What happens is
that the immune system mistakes a harmless substance (such as pollen)
for a deadly germ/virus. Every time you are exposed to a substance
there is a chance that you can become allergic to it. Many people can
go for years without an allergy becoming apparent then have it
suddenly appear. Others can never develop the allergy despite
constant exposure. There is no connection between vaccinations and the development of
allergies. Here is the short explanation. For one with all the gory details,
find a good text on immunology [such as Klein's 'Immunology']: During your entire life, by means of genetic rearrangement, your body
makes antigen-binding portions of a wide variety of immunoactive
molecules. These antigen-binding proteins 'recognize' the shapes of
various molecules. Two molecules with very similar shapes can cause a
cross-reaction to occur, so that the antigen-binding protein will
recognize both of them. Further, during the genetic rearrangements,
refinement and amplification of shape recognition occurs; so that once
you have had an original cross-reaction, it is much more probable that
you will start to produce antigen-binding proteins highly specific to
BOTH molecules. If the antigen binding protein becomes attached to
the constant region of an IgE molecule, you then have an allergy
antibody to the molecule in question. So, completely without outside
influence, one can become allergic to molecules to which one was not
previously sensitive. In people with severe allergies or asthma,
there seems to be a preference for the production of IgE.
Or, as my doctor once put it: The more things to which you are
allergic, the more things to which you will be allergic.
