I get the same things! Ive been to a skin specalist along time ago and she first told me that alot of teenagers get it on there arms, shoulders, back and legs and that it was caused from stress
She gave me cream but i didnt find it helped, the next time i went to visit her she told me it was from the sun. Anyway i havent been back for along time and its getting worst i have it everywhere my arms are alll reddd now like little bumps like there scared becausee i was bad and i kept picking them and squeezing them too i also have them on my legs but there not that bad its just alittle bit near my knee. I know its not fun and not the best looking and its hard because they bug me and i pick them to but if i were you dont pick them because it makes it worst and it will ruin your skin my arms are bad now. Sorry i know i wasnt much help because i dont really know what there caused from but it could be the sun? i dont know but i too would like to know if anyone knows of something that might help or if there is anything out there that might help the redness or scars to make them less noticeable. Thanks...Good luck Kirsty i hope you find something.