My 7yr old grandson had a line about 3ins. long break out on his arm then a day later another line on his stomach about 4ins. long. they're about 1/8 to 3/16 in. bumps in a line that is slightly curved. I just noticed another line on the other side of his stomach. It doesn't look severe, and don't seem to bother him much but they have me concerned? I've never seen anything like them,,, they're the same as his skin color but all 3 lines are just one bump after another and unusual?