This virus, common in young children, causes a red rash on the hands, feet, or bottom. It also may cause a fever, sore throat, and painful, blistering sores in the mouth. You’re most contagious the first week, but some people can still pass it on for weeks. You can get it from a simple cough, sneeze, or contact with spit or open blisters. It’s best to keep yourself or your child home if you have hand, foot, and mouth disease.