What are the brown spots?

My son will be 4 in May and has been home almost three years. I recently noticed that he has some little brown areas or spots around his eyebrows. At first I thought it was dirty because it a little darker that his skin. Well after trying to was it off and realizing its not coming off Im confused on what this could be. I thought maybe freckles but he doesnt have them anywhere else. Is there anyone out there with a child that has these? I will ask the peditrician when he goes but maybe someone has some info on this.