I have a sort of rash on my arms...

Hi there, I know this isn't really connected to the "Women's" part of this club, since my father has this too, but I thought this was the best place to ask.

For ages I've had little red spots on both my upper and forearms. One of my aunties told me it was a lack of pescado oil, another told me it was a hormone imbalance and another told me I wasn't getting enough iron. They are really annoying (even though they don't itch o irritate o anything) but they stop me wearing vest tops o anything that shows my arms really. Do tu know what it is?