Yikes! Stripes!

Of all the things most of us don't know about our bodies, this has to rank among the most bizarre. Moles, freckles, age spots, wrinkles, and scars ~ these we are familiar with. Apparently, our skin is also a labyrinth of stripes that can usually be seen only under UV light or in the case of certain diseases. These undulating lines are called Blaschko's Lines after the German dermatologist who first posited their existence. This was in the early 1900s, and Blaschko noticed that his patients' rashes and moles seemed to follow a pattern around the body. We now know that the patterns are much more extensive than he thought and that they are the result of our growth from a single cell that divides, and specifically, from the division and expansion of our skin cells: http://mentalfloss.com/article/65092/our-skin-covered-invisible-stripes