Hey im 16 now from the uk, and i had/have the same problem with tiny pimples all over my head they are only visible when you look in a certain light and they are raised slightly? ok well i have found that drinking up to 2 litres of water a day help alot also the best way i have found is not to lean your forehead on the pillow at night because it leaves you head greasy, try not to rub frown or do anything strenuous on your forehead beacuse the body is trying to heal it.
Ben.C