look up scabies. it could be that.
I believe they are a mild case of warts.
heat rash???
Look into Eurthema Multiforme, I probably spelled that wrong but google will correct it for you.
Sounds like Keratosis Pilaris, also known as "chicken-skin" because the bumps look like "goosebumps". The keratin that is normally shed and sloughed off your skin is being backed up in your hair...
Eczema