What Causes Raised Bumps On Tongue After Antibiotic Treatment?

I had a slight temperature, heavy productive cough and head cold for a week so I went to see my doctor. He saw inflammation around the larynx and trachea, acknowledged my throat looked sore and said I also had a blocked ear. He prescribed Erythromycin, an antibiotic, due to my husband having had Staph very recently and the likelihood that he could have passed it to me. I have been taking the antibiotic, paracetamol, ibuprofen and a steroid spray for 4 further days now. The coughing has been very intense but I feel it is starting to ease a little. I have been breathing shallowly to avoid coughing, which brought on sinus tachycardia. I now have an upset stomach and a sore spot-like raised area on my tongue. The spot looks white. So the cough is starting to clear but I wondered about the spot. Surely if I am getting better I shouldn't be getting new symptoms? I just wondered if this signals that I need to go back to my doctor. Thanks, Alison