Red rash from ferrets

I work for a pet store that sells ferrets. Every time we clean their cage we get red bumps all over our body that look just like chicken pox. The rash lasts anywhere from 3 days to a week. 7 different workers have gone to the dr for the rash and was told that it was an alergic reaction to something. I have a ferret at home and hold it all the time and am fine but the moment I clean one of the cages at work I break out with this rash. The drs have said that they are not mite bits. Any idea what this could be from? Ferrets are healthy and have no medical problems.