I went to the ER on Saturday (4 days ago) with a sore throat (little white patches on tonsils), fever, chills, dizziness, headache, and body aches. Got a rapid strep test and it was negative, they did give me antibiotics and prednisone . I have been taking my medications and everything but my sore throat has gone away. I still have white patches on my tonsils and it is very difficult to swallow and it painful. What could be the cause?