Hi, Thanks for posting in HCM. I understand your concern. Red lump on the breast with oozing pus indicates skin infection called furunculosis . Since the pus has come out, it should subside soon. Kindly clean the wound using mild antiseptic like Savlon twice daily. Then you can apply Neomycin cream on the lesion. Keep the area healthy and prevent it from getting infected. Also take anti-inflammatory medications containing Ibuprofen to reduce pain and promote faster healing. Hope the information provided would be helpful. All the best.