My dentist gave me Clindamycin HCL 300mg. I first felt a tingling in my scalp, and the next day, after having taken 6 tablets my skin broke out in a rash that is now, 4 days later, covering much of my body. My doctor gave a cortisone shot two days ago, but the rash is still expanding. Can you give me information on what to expect, and what can be done to stop the rash? Thank you.