Hand, foot and mouth disease is a viral illness that primarily affects children aged 10 and under. It’s caused by the coxsackie virus, and its main symptoms are sores in the mouth and a rash on the hands and feet. There is currently no vaccine for this mild illness, but there are steps families can take to prevent it.  Hand, foot and mouth disease is often confused with foot and mouth disease (also known as hoof and mouth disease), a viral disease found in farm animals. Hand, foot and mouth disease cannot be transmitted between humans and animals. In the United States, hand, foot and mouth disease is usually seen in the summer or early fall when the temperatures are warmest.