If the rash is not causing any major issues, it is better to continue with the medication. The concern is for a severe allergic reaction that could cause swelling of the throat or difficulty breathing. However, if the rash is very problematic (painful, intensely itchy, all over the body) or if there are signs of difficulty breathing or swallowing, the medication should be stopped immediately. Usually, symptoms of an ear infection improve significantly within 48-72 hours of starting the antibiotic. Sometimes, rashes can appear due to the fever caused by the ear infection itself.