To dream of a skin rash represents frustration about noticing something being wrong when it shouldn’t be. Something is not normal and you don’t like it. It may also reflect annoyances that you feel stuck with that you don’t have the experience or knowledge to deal with on your own. A rash in a dream is signal that a problem needs extra attention.
A rash in a dream may be a sign that you need to keep pressuring other people to finally help you do something about a problem. You may also be wasting your time putting up with something.
Consider the location on the body of the rash for additional meaning.
A rash on the face may reflect feelings that something is wrong with who you are or how you act and not knowing how to stop it.