What Causes Itchy Rashes Around Moustache And Beard Area?

I have a few infection spots around my moustache and beard area 3 to 4 days after shaving. What seemed to be pimples are now wounds due to me shaving with a rusty blade. Now, even minor grazes for example paper cuts, will have tiny rash dots appearing around it. And the rashes are extremely itchy only when touched. What are these symptoms of?