Among the various factors that cause dry nipples, are skin conditions; hormonal changes and irritation from clothing or personal care products. It is recommended to seek the advice of a dermatologist for an accurate diagnosis and proper treatment. They are able to look at the injury site and offer advice based on what is causing it, making sure you get treated in the best possible way for your condition.

Difficult to answer this question without examination and history, though broadly speaking sinister cause like cancer is rare in such young age, benign skin problems are more common. However it'll be advisable to visit a surgeon for evaluation..

This can be due to multiple reasons. Would need to be checked in OPD.

Nipple dryness maybe related to some skin problem. Please Consult the dermatologist. Breast cancer sometimes causes nipple retraction or nipple discharge