First of all congratulations regarding the results of the lymph gland. I can only guess what the redness is since I have not examined your case in person. I think you should inform your doctor as it could be an inflammation / infection which requires antibiotic therapy. Paget's disease of the nipple (which is a cancer) can present with a picture similar to dermatitis / eczema that does not respond to antibiotics.
Please have a doctor check it out.
Dr. Tamer Fouad, MD
MB, BCh, MSc Internal Medicine.
Consultant of Hematology - Oncology.