Herpetic stomatitis is a viral infection of the mouth that causes ulcers and inflammation. These mouth ulcers are not the same as canker sores, which are caused by a different virus.
Stomatitis - herpetic
Causes, incidence, and risk factors
Herpetic stomatitis is a contagious viral illness caused by Herpes virus hominis (also herpes simplex virus, HSV). It is seen mainly in young children. This condition is probably a child's first exposure to the herpes virus.
An adult member of the family may have a cold sore at the time the child develops herpetic stomatitis. More likely, no source for the infection will be discovered.