Good Morning J., Definitely see your OB, it does sound like a allergic reaction. I had a hysti in 87, so I never went through menopause, but it can happen just about any time dear heart. Have heard of women in their 20's going through it. I stopped HRT several years ago also, got tired of sticking my leg once a month. I don't have flashes, flushes or night sweats either.
The only thing I was ever allergic to was our oldest son LOL a week before he was born. Had the same ikies you are having itching, rash under the skin.. etc. Went into labor and it all went away never to return.
God Bless you J., definitely see your OB.
K. Nana of 5