Mastitis: This is an inflammation of the breast tissue, which can be caused by an infection. It's a common condition in lactating women but can also occur in non-lactating women. The use of danzen (danazol) or myoflex (likely a muscle relaxant or a brand name for a medication) could potentially contribute to or exacerbate mastitis, especially if the medication affects milk production or ductal patency in lactating women.

Ductal Ectasia: A condition where the milk ducts in the breast become widened, leading to inflammation and possible infection. This could cause pus discharge from the nipple.
Periductal Mastitis: An inflammatory condition affecting the ducts under the nipple. It can cause nipple discharge, including pus, and is more common in smokers.
Breast Abscess: A collection of pus in the breast tissue, which can be a complication of mastitis. It's a possible cause of pus from the nipple, especially if the abscess ruptures into a duct.

Inflammatory Breast Cancer: A rare and aggressive form of breast cancer that can cause symptoms similar to mastitis, including redness, swelling, and warmth of the breast. It's crucial to rule out cancer in cases of persistent or severe inflammation.
Tuberculosis of the Breast: Although rare, breast tuberculosis can cause chronic inflammation, abscesses, and fistulae, leading to pus discharge from the nipple.

Granulomatous Lobular Mastitis: A rare inflammatory condition of the breast that can mimic cancer or infection. It can cause abscesses and fistulae, leading to discharge.
Zuska-Atkinson Syndrome: A rare condition characterized by recurrent subareolar abscesses, often associated with ductal ectasia. It can cause chronic discharge, including pus, from the nipple.