[Hand, foot and mouth disease--more than a harmless "childhood disease"]

Hand, foot and mouth disease (HFMD) is a highly contagious, world-wide distributed viral illness that affects predominantly children. It is caused by several enteroviruses, such as coxsackieviruses A6, A10, A16 and enterovirus 71. In most cases, HFMD follows a benign and self-limiting course. After an incubation period of 3 to 10 days, fever and sore throat, the first symptoms of the disease, appear. A few days later, maculopapular or vesicular eruptions form on the palms and soles as well as in the oral cavity. Since the year 2000, several large HFMD outbreaks have been reported in many Asian regions such as China, Malaysia and Vietnam. In some of these outbreaks, high incidences of severe progressive HFMD forms with some fatalities were observed. Such diseases have been caused primarily by enterovirus 71 strains and were characterized frequently by sudden onset of fever, encephalitis/meningitis and severe respiratory symptoms such as pulmonary edema. Further severe neurological and cardiac complications have also been observed during these outbreaks. Recently, some HFMD outbreaks caused by the coxsackievirus A6 have been reported in several parts of the world. These illnesses also affected adults and were characterized by more severe symptoms of "classical" HFMD. In addition, outbreaks of coxsackievirus-A6-associated HFMD in many countries were associated with onychomadesis, with the loss of nails occurring up to two months after initial symptoms. Treatment of "classical" HFMD is usually symptomatic, a generally recommended antiviral therapy does not exist. In severe HFMD cases, suitable treatment also encompasses mechanical ventilation, as well as the additional application of antiviral agents such as ribavirin. In the last years, several novel agents with good in vitro and in vivo activity against enteroviruses have been developed. A vaccine against HFMD is not yet available.