|Image is from Wikimedia Commons under a creative commons license.|
This is hand, foot, and mouth disease, also known as HFMD. And no, it is not related to foot and mouth disease (aka hoof and mouth disease), which is seen in livestock. It is also not possible for the two diseases to pass between livestock and people, or vice versa. HFMD is a viral disease most commonly seen in small children, such as the eleven-month-old seen above. Symptoms include the lesions seen above, as well as a rash and fever. Dehydration can be a concern, as the blisters can be quite painful to the point where the child does not want to swallow. The disease is most contagious during the first week, and is passed on by touching secretions of an infected person. It is also quite possible to have the virus and be asymptomatic.
There is no vaccine, so prevention includes the standard hand washing, disinfection, and avoidance of close contact. Like so many viral illnesses, the only real cure is to let it run its course and treat symptoms. Medication can be given to help with fever and pain, including production to numb the mouth. Complications associated with this disease are possible, but quite rare.
Source is the Centers for Disease Control and Prevention.