Causes: It is caused by yeast called Malassezia, which normally exist in small numbers on the skin. Certain conditions however, can cause the overgrowth of the yeast, causing the development of white and reddish-brown spots on skin.
The 3 men all escaped and made it back to the Britain.   The Great Escape shown in the film happened in March 1944 having been planned first in January 1943. It consisted as per the film of 3 tunnels Tom Dick and Harry, Tom being discovered by the Gestapo.
About the Real Great Escape. Back in 1963, a film was released called The Great Escape. It was an American-made film about an escape by Allied prisoners of war from a German PoW camp during World War II, and starred Steve McQueen, James Garner and Richard Attenborough.