A new study found that women have a greater variety of bacteria on their hands than men do. Also, the bacteria on one of your hands do not necessarily match the bacteria on the other.

http://www.cnn.com/2008/HEALTH/condi...tml#cnnSTCText

My interest in this stems from the fact my mother has chronic contact dermatitis on one of her palms, but not the other. When the doctor asked her what she touched with her left hand but not the right, she replied "my right hand".