when in doubt always take your cat to a vet. One of my cat got something simillar to what you have describe. Initially I thought it was some fungal attack but my vet diagnose otherwise. So she is currently under the vet prescribed treatment..
Yes cats can get rashes.Most times it warrants a Vet visit.It could be anything from food allergy,mange,ring worm, to many other things.
I would suggest taking your cat to the Vet to get the right diagnoses and treatment.