Hi
@Raoul VanMulders and welcome to the forums. Is the rash all over your body or just at the injection sites?
I have heard of allergic reactions to insulin, but my (limited) understanding is that they are normally caused by the chemicals used as preservatives for the insulin.
The obvious thing to do is to talk to your medical team. If it is the insulin (and I have no idea if it is) it is possible that a different type of insulin may resolve the issue.
Good luck