I wear cotton camisoles instead of a bra, because bras have that ployester band, which causes
me to sweat, and get an itchy rash
. I wear all light cotton, and I know I look awful without the bra ( but not according to my husband), so I do also use a light button down shirt, if I'm in a crowd.
Driving in the sun makes it bad for me, so you can your car fan/air-condit, and block the sunb from going on your arm.
Any product with fragrance is supposed to cause the itching.