It's more likely to be a bug or lice ... not necessary caught from the creek, but most probable.

Have you got long or short hair ?

Have you sighted anything crawling in your head?

There may be eggs as well, and this causing your head to itch and create flakes ...

have you seen a doctor and got it checked out ?.

If you try dousing your head and hair in hair conditioner, (this will kill Lice) and combing thru with a 'lice comb' and repeat this until traces of the 'eggs' are gone. It doesn't matter what brand of conditioner, but Medicated or Tea-tree is best, as it gives a cooling effect (to stop the itching) and stimulates the natural oils in the skin to produce natural healing.

Let me know if this helps, and keep us posted..

Ginger