Dear Practo User, The skin of areola (area around nipples) and nipple is very sensitive, Your problem can be due to fungal infection / chemical irritation/ breast skin disorders ( eczema, Paget's disease -which is  usually seen in older age groups) . Few most commonly encountered causes are 1) left over detergent in garments 2) wearing of improperly dried undergarments ( specially if u dry them indoor) 3) Improper hygiene of area ( which includes cleaning , drying, Moisturizing) 4) reaction to latex in the bra ( if they are not cotton) Try resolving above issues , if irritation persist , an examination will be needed.