Inflammatory breast cancer

I have recently been told that I have inflammatory breast cancer. I strongly suspected this due to my symptoms, but I was initially told they were probably just a result of my lymph nodes being blocked. After a skin biopsy, it was confirmed that there were cancerous cells found in the skin of my breast.I am confused about what this means- would it now be classed as stage four, or is it still locally advanced? I’m told the treatment will stay the same- chemo first, then mastectomy, followed by radiotherapy. I do not know a lot about inflammatory breast cancer, has anyone been through the same? Any thoughts/ experiences are appreciated.