I Have A Bad Rash On My Stomach That Has

I have a bad rash on my stomach that has been there for a few days. I also had a rash on my leg about a week ago it is now pretty much gone but now the one on my stomach popped up so now I am concerned. I’m not sure if they are correlated but very weird. I do have sensitive skin and when get bit by my cat on hands or feet I get hives because I am sensitive to cats but I have never had a rash like the one on my stomach it is very red itchy and blotchy has little hives all over. Right before I got the rash on my leg I had gotten a spray tan and was also on vacation for 2 days on a beach so idk if that had anything to do with it but the spray tan is gone now and the one on my stomach came later and worse.