Generally, HFMD is a clinical diagnosis. It most frequently affects children younger than 5 years. It is caused by one of several serotypes of enterovirus, typically coxsackievirus A16, although coxsackievirus A5, A7, A9, A10, B2, and B5 have also been implicated in HFMD in the United States. In Southeast Asia and China, enterovirus 71 has been associated with outbreaks of HFMD with associated neurological complications, including encephalomyelitis. Epidemics of HFMD often occur during the summer and fall. Typically, HFMD begins with a low-grade fever, malaise, and pharyngitis, with mucocutaneous manifestations appearing 1 to 2 days later. The typical lesions are often limited to macules, papules, and/or vesicles involving the palms and soles as well as painful erosions (herpangina) involving the oral mucosa. As with all enteroviral infections, HFMD is transmitted via the fecal-oral route and can be transmitted via contact with saliva, vesicular fluid, respiratory secretions, and feces.