Hand, foot, and mouth disease

Hand, foot, and mouth disease
Typical lesions around the mouth of an 11-month-old boy
Specialty	Infectious disease
Symptoms	Fever, flat discolored spots or bumps that may blister[1][2]
Complications	Temporary loss of nails, viral meningitis[3]
Usual onset	3–6 days post exposure[4]
Causes	Coxsackievirus A16, Enterovirus 71[5]
Diagnostic method	Based on symptoms, viral culture[6]
Prevention	Handwashing[7]
Treatment	Supportive care[8]
Medication	Pain medication such as ibuprofen[9]
Frequency	As outbreaks[1]

Hand, foot, and mouth disease (HFMD) is a common infection caused by a group of viruses.^[10] It typically begins with a fever and feeling generally unwell.^[10] This is followed a day or two later by flat discolored spots or bumps that may blister, on the hands, feet, and mouth, and occasionally buttocks and groin.^[11][2][1] Signs and symptoms normally appear 3–6 days after exposure to the virus.^[4] The rash generally goes away on its own in about a week.^[8] Fingernail and toenail loss may occur a few weeks later and these then regrow.^[3]

The viruses that cause HFMD are spread through close personal contact, through the air from coughing, and the feces of an infected person. Contaminated objects can also spread the disease.^[7] Coxsackievirus A16 is the most common cause and Enterovirus 71 is the second-most common cause.^[5] Other strains of coxsackievirus and enterovirus can also be responsible.^[5][12] Some people may carry and pass on the virus despite having no symptoms of disease.^[10] Other animals are not involved.^[7] Diagnosis can often be made based on symptoms. Occasionally throat or stool sample may be tested for the virus.^[6]

Handwashing may prevent spread and those infected should not go to work, daycare, or school.^[7] No antiviral medication or vaccine is available, but development efforts are underway.^[13] Most cases require no specific treatment.^[8] Simple pain medication such as ibuprofen or numbing mouth gel may be used. Occasionally intravenous fluids are given to children who are unable to drink enough.^[9] Rarely viral meningitis or encephalitis may complicate the disease.^[3]

HFMD occurs in all areas of the world.^[14] It often occurs in small outbreaks in nursery schools or kindergartens.^[1] Large outbreaks have been occurring in Asia since 1997. It usually occurs during the spring, summer, and fall months.^[14] Typically it occurs in children less than five years old, but can occasionally occur in adults.^[10][1] HFMD should not be confused with foot-and-mouth disease (also known as hoof-and-mouth disease) which mostly affects livestock.^[15]

Signs and symptoms

Rash on palms of the hands.

Rash on hand and feet of a 36-year-old man

Rash on the soles of a child's feet

Common constitutional signs and symptoms of the HFMD include fever, nausea, vomiting, feeling tired, generalized discomfort, loss of appetite, and irritability in infants and toddlers. Skin lesions frequently develop in the form of a rash of flat discolored spots and bumps which may be followed by vesicular sores with blisters on palms of the hands, soles of the feet, buttocks, and sometimes on the lips.^[16] The rash is rarely itchy for children,^[4] but can be extremely itchy for adults. Painful facial ulcers, blisters, or lesions may also develop in or around the nose or mouth.^[1][17][18] HFMD usually resolves on its own after 7–10 days.^[17]

Cause

The viruses that cause the disease are of the Picornaviridae family. Coxsackievirus A16 is the most common cause of HFMD.^[5] Enterovirus 71 (EV-71) is the second-most common cause.^[5] Many other strains of coxsackievirus and enterovirus can also be responsible.^[5][12]

Transmission

HFMD is highly contagious and is transmitted by nasopharyngeal secretions such as saliva or nasal mucus, by direct contact, or by fecal-oral transmission.

Diagnosis

A diagnosis usually can be made by the presenting signs and symptoms alone.^[17] If the diagnosis is unclear, a throat swab or stool specimen may be taken to identify the virus by culture.^[17] The common incubation period (the time between infection and onset of symptoms) ranges from three to six days.^[4]

Prevention

Preventive measures include avoiding direct contact with infected individuals (including keeping infected children home from school), proper cleaning of shared utensils, disinfecting contaminated surfaces, and proper hand hygiene. These measures have been shown to be effective in decreasing the transmission of the viruses responsible for HFMD.^[17][19]

Vaccine

A vaccine known as the EV71 vaccine is available to prevent HFMD in China as of December 2015.^[20] No vaccine is currently available in the United States.^[19]

Treatment

Medications are usually not needed as hand, foot, and mouth disease is a viral disease that typically resolves on its own. Currently, there is no specific curative treatment for hand, foot and mouth disease.^[17] Disease management typically focuses on achieving symptomatic relief. Pain from the sores may be eased with the use of analgesic medications. Infection in older children, adolescents, and adults is typically mild and lasts approximately 1 week, but may occasionally run a longer course. Fever reducers and lukewarm baths can help decrease body temperature.

A minority of individuals with hand, foot and mouth disease may require hospital admission due to complications such as inflammation of the brain, inflammation of the meninges, or acute flaccid paralysis.^[12] Non-neurologic complications such as inflammation of the heart, fluid in the lungs, or bleeding into the lungs may also occur.^[12]

Complications

Complications from the viral infections that cause HFMD are rare, but require immediate medical treatment if present. HFMD infections caused by Enterovirus 71 tend to be more severe and are more likely to have neurologic or cardiac complications including death than infections caused by Coxsackievirus A16.^[17] Viral or aseptic meningitis can occur with HFMD in rare cases and is characterized by fever, headache, stiff neck, or back pain.^[12][17] The condition is usually mild and clears without treatment; however, hospitalization for a short time may be needed. Other serious complications of HFMD include encephalitis (swelling of the brain), or flaccid paralysis in rare circumstances.^[16][17]

Fingernail and toenail loss have been reported in children 4–8 weeks after having HFMD.^[4] The relationship between HFMD and the reported nail loss is unclear; however, it is temporary and nail growth resumes without treatment.^[4][21]

Epidemiology

Hand, foot and mouth disease most commonly occurs in children under the age of 10^[4][17] and tends to occur in outbreaks during the spring, summer, and fall seasons.^[5] HFMD is most commonly caused by infection with Coxsackievirus A16.^[5]

Major outbreaks

• In 1998, there was an outbreak in Taiwan, affecting mainly children.^[22] There were 405 severe complications, and 78 children died.^[23] The total number of cases in that epidemic is estimated to have been 1.5 million.^[5]
• In 2008 an outbreak in China, beginning in March in Fuyang, Anhui, led to 25,000 infections, and 42 deaths, by May 13.^[5] Similar outbreaks were reported in Singapore (more than 2,600 cases as of April 20, 2008),^[24] Vietnam (2,300 cases, 11 deaths),^[25] Mongolia (1,600 cases),^[26] and Brunei (1053 cases from June–August 2008)^[27]
• In 2009 17 children died in an outbreak during March and April 2009 in China's eastern Shandong Province, and 18 children died in the neighboring Henan Province.^[28] Out of 115,000 reported cases in China from January to April, 773 were severe and 50 were fatal.^[29]
• In 2010 in China, an outbreak occurred in southern China's Guangxi Autonomous Region as well as Guangdong, Henan, Hebei and Shandong provinces. Until March 70,756 children were infected and 40 died from the disease. By June, the peak season for the disease, 537 had died.^[30]
• The World Health Organization reporting between January to October 2011 (1,340,259) states the number of cases in China had dropped by approx 300,000 from 2010 (1,654,866) cases, with new cases peaking in June. There were 437 deaths, down from 2010 (537 deaths).^[31]
• In December 2011, the California Department of Public Health identified a strong form of the virus, coxsackievirus A6 (CVA6), where nail loss in children is common.^[32]
• In 2012 in Alabama, United States there was an outbreak of an unusual type of the disease. It occurred in a season when it is not usually seen and affected teenagers and older adults. There were some hospitalizations due to the disease but no reported deaths.^[33]
• In 2012 in Cambodia, 52 of 59 reviewed cases of children reportedly^[34] dead (as of July 9, 2012) due to a mysterious disease were diagnosed to be caused by a virulent form of HFMD.^[35] Although a significant degree of uncertainty exists with reference to the diagnosis, the WHO report states, "Based on the latest laboratory results, a significant proportion of the samples tested positive for enterovirus 71 (EV-71), which causes hand foot and mouth disease (HFMD). The EV-71 virus has been known to generally cause severe complications amongst some patients."^[36]
• HFMD infected 1,520,274 people with up to 431 deaths reported at the end of July in 2012 in China.^[37]
• The governorate of Daraa in Syria reported over 200 cases of HFMD there in early 2015.^[38] These were due to the central Syrian government denying the region water chlorination.

History

HFMD cases were first described in New Zealand in 1957.^[17]

Research

Novel antiviral agents to prevent and treat infection with the viruses responsible for HFMD are currently under development. Preliminary studies have shown inhibitors of the EV-71 viral capsid to have potent antiviral activity.^[13]

References

External links

Media related to Hand, foot and mouth disease at Wikimedia Commons News related to Highly contagious Hand, foot and mouth disease killing China's children at Wikinews