I love cats but i have terrible allergies to them.  It is an alergic reaction to something the cat produces.  Are you allergic?
Oh no! I wonder if it is to the cat's dander? No I am not alllergic to cats. What symptoms do you experience?
I have a coughing fit, wheezing, chest tightening, itching, rash, watering eyes - you name it.  I get it!
That's awful. Have you seen a doctor about it?
Yes the doctor just explained that an allergen is a type of antigen that produces an abnornally vigorous immune response. and he basically recommended that I stay away from cats.  Not much else can be done aparently.
Wow, that's no fun at all.
Nope.  My immune system just doesnt cope with cats.  It works well detecting a wide variety of agents known as pathogens that it does not like, then it reacts! its ok though I just have dogs instead.  They are lovely pets to have too.