Once I have given Nellie her flea medication (Frontline) it dried to quickly and left a white marking on Nellies neck (fur and skin)...does Noodles have the scab on the skin or fur?!

Maybe when it only occurs after given flea treatment you should switch to another product.
But I would ask the vet, just to be sure it's not a serious skin irritation...

Hope this has helped you at least a tiny bit...
Noodles is a real cutie pie!!! (Thanks for the picture)