Hand, foot, and mouth disease (HFMD) is an infection caused by germs called enteroviruses. HFMD is often a mild infection but in rare cases can lead to a more serious illness. HFMD is easily spread when in close contact with an infected person. The illness is called HFMD because it usually causes a rash on the hands, feet, and inside the mouth. The skin rash usually does not itch but painful blisters may form. Symptoms: general malaise, sore throat, and fever.