welcome to healthcare magic
yes your doctor is right that the development of the skin rash
has no connection with prialt
though one of the side effect of the drug is getting purple spots on the skin meaning you are a developing a problem to clot your blood easily.
your rash could just be a fungal infection
it it is itchy in nature
it could be a bruise
that you might have gotten when you injured yourself.
it could also be a start of a skin infection
would suggest observe the skin for any other changes and at the same time you can get a blood check up done with inr to rule out that it is not a side effect of the drug you are been given.
hope have helped to answer your query
wish you a quick recovery.