Hand-foot-mouth disease (HFMD) is a relatively common viral illness characterized by fever, rash on the hands and/or feet, and blister-like eruptions in the mouth. Although it can develop in adolescents and adults, HFMD primarily affects children under the age of 10 years.
HFMD is caused by enteroviruses, including Coxsackie virus A16 and enterovirus 71 (EV71). Enteroviruses are transmitted from person to person via direct contact with saliva, discharge from the nose or throat, fluid from blisters, and feces of an infected person, and by both fecal-oral and respiratory routes. The fecal-oral route of transmission usually occurs in environments with poor sanitary conditions; respiratory transmission is more common in developed regions/countries. There is usually a 4–6 day incubation period, followed by the development of red spots that evolve into painful ulcers in the mouth (e.g., on the gums or tongue) and by a rash with blisters that appears on the hands, feet, and buttocks. The blisters have reddish borders and are lightly colored in the center. HFMD is usually benign and self-limiting, and complete recovery usually occurs within 7–10 days. Complications are rare but include viral meningitis, encephalitis, acute flaccid paralysis, pulmonary edema, myocarditis, pneumonia, and rhabdomyolysis with anuric renal failure.
HFMD can usually be diagnosed based on clinical presentation. When laboratory confirmation is necessary, the causative virus can be cultured from a variety of sites, including oral ulcers, cutaneous lesions, nasopharyngeal discharge, and cerebrospinal fluid (e.g., in cases of suspected central nervous system involvement). Treatment is supportive and focused on providing symptomatic relief; antibiotics are not indicated and there is currently no effective antiviral agent specific to the causal virus.
Facts and Figures
HFMD is highly contagious; approximately 50% of those exposed to a causative virus (who do not have immunity to the virus) will develop HFMD. Patients with HFMD are considered contagious as long as fever is present. Patients infected with EV71 are at high risk for spreading pathogens in the first 2 weeks of infection; although EV71 excretion can linger for months after acute infection, in most cases lab test results are negative two weeks after onset.
In temperate climates, outbreaks are more frequent in the summer and early autumn months. HFMD often occurs in childcare centers and schools. HFMD has emerged as a public health concern in Asia following recent outbreaks of HFMD caused by EV71. To date, more than 900,000 cases of HFMD have been reported in Mainland China.
Risk Factors
The most important risk factor is age; children under 10 years of age are at high risk for infection. Exposed adults who do not have antibodies to the causative virus are also at increased risk.
Signs and Symptoms/Clinical Presentation
Oral lesions, which evolve into gray vesicles and appear as gray ulcers
Skin lesions that evolve into gray vesicles
Fever that is usually about 101 °F (38.3 °C)
Sore throat
Headache
Non-pruritic rash with blisters on palms of hands, soles of feet, buttocks, perineum, and pads of the fingers
Loss of appetite
Assessment
Patient History
Ask about onset, duration, and severity of fever and other signs and symptoms
Laboratory Tests That May Be Ordered
Culture and immunoassay of cutaneous lesions, mucosal lesions, or stool samples can identify the causative virus
Reverse transcription-loop-mediated isothermal amplification (RT-LAMP) assay is a quick, low-cost, and highly sensitive method to detect enterovirus 71 (EV71) HFMD infection, particularly for those patients within primary care institutions, field environments, or developing countries
Polymerase chain reaction (PCR) testing can identify the causative virus
Treatment Goals
Promote Symptomatic Resolution and Reduce Risk of Complications
Monitor vital signs (especially temperature), assess all physiologic systems, assess for pain, and review lab results; administer acetaminophen, ibuprofen and other symptomatic relief, as ordered
Avoid use of aspirin in children and adolescents because of the risk of Reye’s syndrome
Apply topical lidocaine for ulcers, if ordered
Encourage increased fluid intake (e.g., milk, water, nonacidic juices) to prevent dehydration; provide I.V. fluids for patients with severe dehydration, as ordered
Assist with rinsing the mouth with salt water, as appropriate in older child, adolescent, and adult patients
Monitor closely for complications (e.g., viral [i.e., aseptic] meningitis, encephalitis, acute flaccid paralysis, pulmonary edema, myocarditis, pneumonia), including seizures related to high temperature; follow facility protocols for seizure precautions as appropriate (for more information on signs and symptoms indicating central nervous system involvement, see Red Flags, below)
Prevent Further Transmission, Educate, and Provide Emotional Support
Follow facility infection control protocols to prevent transmission
Assess patient/family member anxiety level and coping ability; provide emotional support, educate, and encourage discussion about HFMD etiology, potential complications, risk factors, transmission prevention, and individualized prognosis
Educate patient and family members to practice strict handwashing to prevent the spread of infection; clean contaminated surfaces at home with soap, water, and diluted bleach solution; and avoid close physical contact and sharing of utensils
Encourage parental visitation and rooming-in per facility protocol for pediatric patients
Food for Thought
HFMD is not related to the similarly named hoof-and-mouth disease, which affects cattle, sheep, and swine
HFMD in pregnancy is not known to cause fetal complications (e.g., congenital abnormalities, stillbirth), although if the pregnant woman has signs and symptoms of HFMD at the time of delivery, the newborn may contract the disease
Red Flags
Red Flags Clinical predictors of central nervous system involvement in patients with HFMD include duration of fever ≥ 3 days, temperature ≥ 101.3 °F (38.5 °C), and the presence of lethargy
Red Flags High fever may cause convulsions
What Do I Need to Tell the Patient/Patient’s Family?
Provide written information on HFMD, if available, and advise patient/parents to seek immediate medical attention for new or worsening signs and symptoms
Advise patients, family members, and childcare workers to wash hands frequently
Reassure patient and family that signs and symptoms usually resolve quickly and that the prognosis is excellent
Explain that the patient should be considered contagious as long as fever is present
Suggest giving an affected child cool liquids, sherbet, and ice cream to reduce risk of dehydration and alleviate oral pain; advise that soft foods may be best tolerated