Male, 56, for months i've had mild pain on left nipple.recently increased to sharp pain; mamm/u.s. both negative.pain still increasing..what 2 check??

Nipple pain: 1. Paget's disease of the nipple - This occurs when externally invisible cancer inside the breast spreads to the nipple and areola area. The areolar area looks as if it has been infected. It looks, red, swollen and is painful but actually this is caused by blockage of small channels called lymphatics which drain the fluid from the areolar area. This blockage is caused by rapid proliferation of cancer cells within the breast tissue.Sometimes the breast cancer may not be apparent even on a mammography. 2. It could also be caused by allergies or sensitivities to various detergents, soaps, weather, fabric,etc. Some women are sensitive to the plastics in breast shells, nipple shields, and pump flanges. 3. Repeated friction like say prolonged exercise or jogging. 4. Vigorous sexual activity could be a cause. 5. Infections of the breast has to be ruled out. Infections could lodge on already traumatized nipples. Diabetes is another risk factor for skin infections because micro-organisms love the sugary cells in people with diabetes. Nipple pain with fever is once reason you should visit the doctor because of the concern for infections.