Weird One with Galaxy S5

Ok so its something and nothing but when it comes to my belongings i prefer them to be in 100% working order
My misses dropped her keys last night and i had to use the flash light on the phone to find them when looking on a dark background i see there is a dead pixel on my screen, when i put my finger over the flash light the dead pixel dissapears but when i let go it comes back
Is this an actual dead pixel or do you think it has something to do with the app im using ?
Answer #1
i would suggest to clean the screen (with the cleaning cloth that comes with the phone to clean the screen) rub on the dead pixel area a little bit and then see weather you solved it or not
Answer #2
is the only time you see it when it is dark?