My 17 yr old son works outdoors mowing & weed wacking. He woke up this morning and I noticed a red mark (a little bigger than a quarter) on the top left side of hia forehead by his hairline. I asked him what is that red mark on your forehead? He said I dont know maybe sunburn. When I took a closer look, it looks to have an apperance of a welt and if you look at it from the side it is raised like a bump. He said it does not hurt. Since he works outside, I was wondering if it could possibly be a bite of some sort. He does have small patches of posion ivy on his arm but they are tiny bumps. Any imput would be greatly appreciated. Thank you in advance to taking the time to read my post.