Just thought I'd add my experience on the subject.  My allergies started
in my early teens which developed into asthma by the time I was 20.  I
grew out of most of them in my 30's but when I got heavily involved in
fostering and working with feral kittens, they came back 10 fold.  Once
I added ferrets to the mix, my asthma was so severe I was placed on
preventive medication for the first time in my life (mid 40's).  If that
wasn't bad enough, anytime I was scratched by a cat, it would develop
into a painful hive, complete with swelling, itching, rash.  Then, about
2 years ago I developed a little round patch on my wrist (thought it was
ringworm at first).  It got progressively worse and then spread to other
parts of my hands and arms which turned out to be eczema.  When I was
completely miserable and wishing I was dead, I finally went to an
allergist and began receiving allergy shots - for cats, not ferrets (by
the way I have 13 - ferrets, not cats).  It actually helped and my asthma
is now under control and I rarely need a rescue inhaler.  Unfortunately,
it did nothing for the eczema and when I pick up to hold and kiss my
ferrets or if I let them kiss me (which I do all the time), it gets the
skin inflamation going and I have to treat it with cortisone cream (which
I fought desperately since I abhor taking or putting any kind of chemical
in or on my body).  It makes no difference where I touch them or where
they kiss me - it will become inflamed, red, itchy and....if I scratch
it, bloody.  If I am in an enclosed room with them for a prolonged period
of time, then the asthma will kick in.
 
I wish I could share a more positive allergy experience but I think it's
only natural that as ferrets become more popular as pets, more allergic
people will surface.
 
For me it's a trade off and since I'm not willing to part with my
animals, I chose to live with my...uh...discomfort.  I'm typically not
the person others complain to about their sneezing fits and watery eyes.
[Posted in FML issue 4393]