How to help son with mouthsores?

Start with easy: First: check with your doc; could be sign of something more worrisome second: try water and salt.

Virus: Viral infections are most common cause of mouth sores. Others are trauma from heat or foreign object. The virus is usually dormant with in you already and then the outbreak is usually a result of stress to the body. Treat the symptoms with topical meds (cankaid, oragel, etc...) and/or see your provider if concerned. They may give you a rx antiviral.