I was taking Tamoxifen during 4 years, after having a couble mastectomy. About a year into the Tamoxifen treatment I got the weardest rash, on my upper chest, all around the neck and all over my face, my ears - and in the bend of the right arm. (Nowhere else on the body) Red, itchy and swelling. It kind of changed and moved around, but still only on the upper chest, around the neck, the face, the ears and the bend of the right arm. After some days my face was swollen and I literally looked like a ninety year old lady (even though I was 39) My eyes were hardly visible at all. And my voice got hoarse. The doctors were trying to find out the reason - without success. The only thing that helped was Prednisone and a couple of prescription creams (Desonide and another I can't remember the name of). The symptoms went away but came back frequently. Finally, after more than a year of struggling, I googled the symptoms and Tamoxifen and found a website were women were posting Q&A's. Many other women had experienced the same thing. I talked to my oncologist and I got off the Tamoxifen for two weeks. Towards the end of the second week my son (5 years old at the time) said: "Mom, you don't look like a dragon any more!!!". I got on Tamoxifen again, and the symptoms returned. Got off, and they disappeared. After trying "on/off 4 times, with exactly the same result we were certain that Tamoxifen caused the problems. I continued the Tamoxifen treatment until 3 years ago and didn't have any problems at all with rash, swelling, itching, etc... UNTIL THIS SUMMER, when I had a small flare up for a week, but it went away on it's own. In November  I had a new huge flare up, just like it was when I was taking Tamoxifen. Got Prednisone and it went away. In December it came back, even worse. My face was so swollen that my friends wouldn't recognize me. Prednisone helped again. Yesterday it came back and I just started a new round of Prednisone. I have some allergies but none of them would explain this reaction. MY OWN CONCLUSION at this point is: Tamoxifen trigged this reaction the first time. Last year I got into perimenopaus. Tamoxifen and perimenopaus/menopaus are both messing with your HORMONES. So now I'm:   1. Going to let my allergist, oncologist, endocrinologist and gynecologist communicate and coordinate hormonial tests and suggest treatments   2. Focus on alternative treatments for getting a better balance of my hormones (in addition to yoga, excercise and meditation)