Sue, I'm not sure what this might be.  Could she be having a severe allergic reaction?  A scaly, rash on the nipple can be a sign of a type of breast cancer called Paget's Disease of the Breast, but that is usually on just one breast.  Also breast symptoms in a 16-year-old are almost never breast cancer.  

Oozing sores sound like she might have an infection that needs a doctor's attention.  If this has lasted more than a few days, it is definitely time to call the doctor.  If it just started and getting to a doctor is difficult for you, you could try treating the sores with a topical antibiotic.  However, the wisest course would be to check with the doctor.  I hope she is better soon.