A sore throat may be due to many different causes. Most commonly a sore throat results from a viral or bacterial infection. Allergies may also be responsible for a sore throat. Sore throat can also be a sign of something more dangerous such as cancer, although this is not common.
Evaluation for a sore throat involves a complete head and neck exam and often a laryngoscopy. Antibiotics are only necessary if there is a bacterial infection such as strep throat, of if another infections, such as a bacterial sinus infection.
Sore throats that persist for some time without treatment merit a full workup and a visit with a physician such as an otolaryngologist. This is to ensure that a cancer or tumor is not a cause of the sore throat.