The Lichtenberg figure- or lightning flower- is a strange phenomenon that occurs in objects, land masses, and people who are struck by lightning. In humans, lightning flowers are thought to be caused by the passage of lightning/shock wave currents flashing over the skin, causing capillaries under the skin to rupture. Here are some photos that substantiate the claim:
As a side note, I do not know why most of these people have such unfortunate taste in bedding/clothing but they survived lightning; they can do whatever the hell they want. If you want to read more about this strange event, here are a couple of sources on the subject and stories from survivors.
(Please note, I understand that Wikipedia is not a reliable source but there is very little information offered on this subject- I would be happy to update this article if you find better referencing material.)