Hand-foot-and-mouth disease (HFMD; synonyms: Hand-foot-and-mouth exanthema; Foot-and-mouth disease; ICD-10-GM B08.-: Other viral infections characterized by skin and mucosal lesions, not elsewhere classified) is a disease caused predominantly by group A enteroviruses (EV-A) that presents with exanthema (rash) of the mouth and palms and soles. Buttocks, genital area, knees or elbows may also be affected. Enteroviruses are small, non-enveloped RNA viruses that belong to the Picornaviridae family.Group A enteroviruses (EV-A) include coxsackie A viruses (A2-A8, A10, A12, A14, A16), enterovirus A71 (EV-A71), and newer serotypes. Coxsackie A16 viruses and coxsackievirus A6 and A10 are the most common cause of HFMK. Note: HFMK should not be confused with foot-and-mouth disease, which occurs in cattle, sheep, and swine. The two diseases are caused by different genera within the Coronaviridae family. Humans are currently the only relevant reservoir of the pathogen. Occurrence: ubiquitous (distributed everywhere). Very large HFMK outbreaks occur regularly in the Western Pacific region (including Malaysia, Singapore, China, Japan). EV-A71 viruses in particular often lead to severe courses with impairment of the central nervous system (CNS) or the development of pulmonary edema (water retention in the lungs) and even death. The contagiousness of the pathogen is high. Manifestation index: 10-20% of HFMK infected individuals manifest (recognizable) hand-foot-and-mouth disease. Seasonal accumulation of the disease: HFMK is diagnosed throughout the year, but particular accumulations occur in late summer and autumn. Transmission of the pathogen (route of infection) occurs through direct contact with body fluids (nasal and pharyngeal secretions, saliva, secretions from vesicles) or stool and contact with virus-contaminated surfaces (doorknobs). In addition to fecal-oral transmission, the virus can also be transmitted by droplets during the first few days after infection. The entry of the pathogen is enteral (the pathogen enters through the intestine or bacteria as feces enter the body through the mouth), i.e. it is a fecal-oral infection. Human-to-human transmission: Yes
Incubation period (time from infection to onset of disease) is usually 3-10 days (1 to 30 days). The duration of illness is usually 7-10 days. In addition to the classical form of HFMK, there is an atypical hand-foot-and-mouth disease (see below “Complaints – Symptoms”). Frequency peak: Occurrence predominantly in children under 10 years of age, but adults can also fall ill. Since HFMK is not compulsorily notifiable nationwide in Germany, there are no valid data on prevalence (disease frequency). The duration of infectivity is during the first week of illness. Infected individuals are highly contagious (esp. when the vesicles ulcerate). Note: Even after symptoms resolve, viruses can continue to be shed in the stool for several weeks, so patients can be infectious for a very long time.Asymptomatic infected persons (mostly adults) are also infectious. The disease leaves immunity only to the causative pathogen; therefore, re-infection with hand-foot-and-mouth disease by one of the other pathogens is possible. Course and Prognosis: Classic hand-foot-and-mouth disease usually begins with general symptoms of fever, low appetite, and sore throat. 1-2 days after the onset of fever, painful enanthema (rash in the area of the mucous membranes) usually develops. This mainly affects the tongue, gums and oral mucosa. Within one to two days, a non-itching exanthema (rash) forms with flat or raised red patches, sometimes blistering. This affects the palms of the hands and soles of the feet. The buttocks, genital area, knees or elbows may also be affected. If necessary, it may also appear as an itchy rash (atypical courses). As a rule, the course of the disease is mild. Within 5 to 7 days almost all patients recover without medical treatment. After about 7-14 days, the skin changes heal without scarring.In atypical hand-foot-and-mouth disease, diseased patients suffer from disseminated (“distributed over the body or certain regions of the body”) skin lesions as well as severely reduced general condition.More than 80% of infections are asymptomatic, i.e., without the appearance of symptoms but with the formation of neutralizing type-specific antibodies. Complications such as polio-like paresis (paralysis) or aseptic meningitis (meningitis)/encephalitis (brain inflammation) are very rare. The lethality (mortality related to the total number of people suffering from the disease) is very low and concerns only cases in which severe complications occur. In pregnancy, most enterovirus infections are mild or asymptomatic. Severe complications are very rare. Most newborns also show a mild course of disease. In very rare cases, systemic infection with fulminant (rapid and severe) courses is possible. Vaccination: A vaccination against HFMK is not yet available. In Germany, the disease is not notifiable according to the Infection Protection Act (IfSG).
