How To Treat Skin Rashes?

Hi, My name is Praveen and chatting from India.. Today, I had a rash kind of infection on my skin and when I touched it.. it was so dry, broke into pieces and came off like as if they were like dandruff ( in pieces). I am so scared as its exactly on my face and I think its spreading too.. what to you think I should do? I have a anti-fungal medication called "Surfaz n".. will that be okay to apply? or is it a serious disease?