Heat Rash Under Breast. Heat rash or sweat rash is a common condition that can affect the skin of the breast to develop red itchy spots like bug bites. It is also prevalent during pregnancy when a woman s breast size increases.
A rash under the breast often results from skin irritation an allergic reaction or heat rash. It is also prevalent during pregnancy when a woman s breast size increases. Chafing between the skin folds which can be caused by wearing a tight bra.
This rash is caused by oil found in the plant called urushiol.
A rash under your breast can be caused by a number of things. Sometimes during this time hormonal changes in the body may lead to heat rashes on the chest and underneath the breast. In women wearing too tight bra can lead to heat rash on breast and under the breast. It is mostly a form of irritant dermatitis and is called intertrigo characterized by inflammation of skin folds.