Thanks for writing to us.
From your history it indeed looks like Hand Foot and Mouth Disease. After the child gets the enterovirus, it takes around 3-6 days to manifest the disease. The child will typically start with sore throat and fever and slowly develop sores in the face, hand, feet, back and buttock region. In some cases there will be blisters. Normally the patient should recover spontaneously within 7 days without any treatment. You can give him tylenol for controlling fever and pain. Ibuprofen, only if the pain is unbearable with ranitidine.
Also at this stage he will be spreading the infection easily. So for the family members, try to avoid direct contact as much as possible, and keep washing your hand. This is because its a community acquired infection and if other people keep getting infected, then the recovery will take that much longer. For his sore throat you can give him ice-cream. That should help.
You can wait for another 2-3 days if there's no fever. If it still doesn't resolve then you can consult your local doctor, whether antibiotics are needed or not.
Do get back to us for further queries,