Hand-foot-and-mouth syndrome: A clinical pattern consisting of a rash on the hands and feet and in the mouth due to a viral infection. The internal rash (the enanthem) consists of blisters and little ulcers that may involve not only the lining of the mouth but also the gums, palate, and tongue. The external rash on the body (the exanthem) typically affects the hands (most commonly), feet and, sometimes, the buttocks. There may also be sore throat, irritability, decreased appetite, and fever.
The syndrome is caused by various viruses, including several types of coxsackievirus- coxsackieviruses A16 (most often), A5, A9, A10, B1 and B3, and enterovirus 71. The incubation period is short, on the order of 4 to 6 days. The disease is most frequent in summer and fall. The rate of clinical expression in hand-foot-and-mouth disease is high with the enanthem-exanthem pattern evident in nearly 100% of preschoolers, nearly 40% of school-age children and about 10% of adults. So a young child might well contract the hand-foot-and mouth syndrome just before or after the start of preschool. The illness is characteristically self-limited and is usually over and done within a week, particularly when due to its most common cause: coxsackievirus A16. In those outbreaks due to enterovirus 71, the illness may be more severe with complications such as viral meningitis and encephalitis and paralytic disease. However, hand-foot-and-mouth disease as a rule is, fortunately, mild and self-limited.
The condition was first reported in 1956 in Australia and by the early 60s had emerged as a common childhood illness around the world. It is also called hand-foot-and-mouth disease and sometimes the hyphens are dropped and it is termed hand, foot, and mouth syndrome (or disease).