Kathy, It is my understanding that this is fairly common & is caused by moisture under breasts, such as from sweating. Have her use a cream or powder OTC prep for athlete's foot. Since I live in Florida, sweating is a common problem that is responsible for more moisture under breasts than bathing! (Too much bathing??? Really!!!!) Since I personally have suffered from excess sweating due to "hot flashes", I found that the powdered athlete's foot prep was a "life saver." Sincerly, Laura Hart Winter Park FL-where it looks like we're in for a long, steamy summer!