Unfortunately quite the opposite. Allergic reactions, particularly
the deadly ones (anaphylactics) tend to increase in severity with
exposure. Check the large amount of info on the internet, this is
a good start:
http://www.emedicinehealth.com/severe_allergic_reaction_anaphylactic_shock/article_em.htm
but please do not expect any allergic reaction to diminish, with or
without treatment unless you luck out with a very good allergist.
Usually they just get worse. Sorry, as we all are.
pavane