When making a business transaction with a salesperson, assuming all goes well, you would anticipate a hand shake upon the conclusion of the sale - right? Usually, I would say that this is the case.
When dealing with salespeople one would assume that a person hired would not have communicable diseases, right? So, knowing that a company allows a person to work for them you would gather that contact with this person would be safe to be in contact with. Are you still with me?
That said, if the person is visually affected with something you are not familiar with, say protrusions or growths on their body, would you assume that they are risk free and be comfortable with a handshake?
Taking this a step further, your salesperson has small growths on their face/eyelids and then along the hands and arms there are large protruding growths, with coloration. Do you welcome the handshake?
If you do shake their hand, how would you feel? Were you forced and now feel the need to cleanse? Would you think nothing of it?
If you don't want to shake, how would you decline a person with an outstretched hand waiting? Do you wonder if you've offended them? Do you care?
**I'll be more specific once I hear reactions from some of you**