I've taken metroprol for close to 10 years and have not developed any sort of rash or had any other signs of allergic reaction.
My comment has to do with the fact that Metoprolol is the cause of my diabetes - I believe. I have come to believe that any med ending in -lol (such as Athenolol) raises a person's blood sugar.
Update to my post of Dec 2018. Turns out Repatha has latex in the injector and I'm allergic to it. That probably caused the rash. Has anyone had this problem with Repatha or Praluent? I'd like to try Praluent.