Itchy skin and hives. Is this due to drop in estrogen levels?

Hi all. Over the last couple of weeks I've been breaking out in hives, particularly on my forearms and now my legs. Skin is very itchy and generally uncomfortable. I've read that a drop in estrogen levels can be a reason for these symptoms. Has anyone else experienced the same thing after a radical hysterectomy?

I was diagnosed with Stage 1b1 adenocarcinoma in October last year. Treatment was a radical hysterectomy with ovaries and lymph nodes removed. 

Would be interested to hear if this is 'normal'! Thanks