If you have reason to refuse a handshake, for example you have been exposed to a virus, you are ill, you have a sore hand, etc., then you simply explain the facts with a sincere smile and step back half a pace. Otherwise there is no good reason to refuse a handshake. Carry antibacterial lotion with you if you have a germ phobia. The H1N1 scare is not reason to toss proper etiquette out the window!
