Welcome to the Healthcare magic platform, I have understood your query. Augmentin contains amoxicillin (which is a penicillin) and clavulanate potassium as active ingredients. However, many people are allergic to penicillin and may present with less severe skin rash, itching, hot flushing, hives or sudden and intense anaphylactic reactions which need emergency medical attention. So, i believe you have experienced an allergic reaction (which presented as hot red face in your case) to augmentin and not from prednisone. Therefore, i think doxycycline has been prescribed correctly for treating sinus infection. Hope this answer is helpful. Please do not hesitate to ask if you have further questions. I will be pleased to serve you. Best regards, Dr. Khoja