[Clinical characteristics and course of hand, foot, and mouth disease]

Hand, foot and mouth disease (HFMD) and herpangina (HA) are common childhood diseases mostly associated with human enteroviruses (EV). Although usually benign illnesses, neurological complications may be observed during large epidemics when enterovirus A71 (EV-A71) is involved, as observed in the Asia Pacific Region and in China since the late 1990s. The occurrence of these complications warrants reinforcing the surveillance of the emergence of EV-A71 infections in France and Europe. Monitoring EV infections associated with HFMD can be considered as an effective tool to detect an upsurge of EV-A71 infections in a timely manner. In 2014, a national sentinel surveillance system for HFMD/HA was set up in France through a network of volunteer pediatricians and coordinated by the National Reference Center for Enteroviruses and Parechoviruses. Although classical manifestations of HFMD/HA can be easily recognized, there are several atypical presentations of the disease that can be confused with other skin conditions. Delayed cutaneous manifestations, such as onychomadesis and acral desquamation, may also occur and should prompt consideration of HFMD in the preceding weeks. Severe complications following HFMD include neurological manifestations (mainly rhombencephalitis) or less frequently cardiopulmonary failure and can sometimes be fatal. In China, the case severity rate has been estimated at 1%, with a case fatality rate at 0.03%. EV-A71 was involved in more than 90% of the fatal cases. Diagnosis of EV infections associated with severe neurological manifestations is based on the molecular detection of the EV genome in vesicles, cerebrospinal fluid (CSF), throat and stool given that EV-A71 is rarely recovered from the CSF. Positive EV genome detection should be followed by EV genotyping to identify the type of the EV. In temperate-climate countries, outbreaks of HFMD occur mostly but not exclusively during summer and autumn months. Adults may also present with HFMD. In 2016, an upsurge of severe neurological manifestations was reported in France; EV-A71 accounted for 50% of the cases. No specific treatment is available, but two inactivated EV-A71 vaccines are currently available in China.