Question: what causes dead skin?

Claire Lee answered on 27 Jun 2013:

Well, your body is made of cells, and all of them die and get replaced. Your skin is just the same. New skin cells are made underneath, and as they get older they move outward, pushed up by more new cells. Eventually when they reach the surface they die after a while and dry up and go all flaky. So dead skin is really just dead skin cells. Exfoliation time!!