@sandii28 I’m so sorry for your pain. I often try to not comment on posts about AIs, because I’m on tamoxifen, but I’ve done a lot of research on them because I needed to choose which hormone therapy I wanted to take.
It is so sad when doctor’s don’t use the knowledge that they have to support their patients. Letrozole and Anastrozole cause a large drop in estrogen. It is what they do, block estrogen. It is a well known fact that lupus flares are affected by hormone fluctuations. Doctors know that women have difficulty with lupus flares during perimenopause, menopause, and childbirth hormone changes.
Many women do have joint pain with AIs alone but the change in estrogen would seem to be a likely cause for a lupus flare.