Hand, foot and mouth disease (HFMD) is a common and highly contagious viral infection that most often occurs in children.

HFMD is caused by members of a group of viruses known as enteroviruses, which enter the body – usually by the mouth – and reproduce in the digestive tract. Children and people with compromised immune systems are more susceptible to the disease because their immune systems have not fully developed or are weak. When the immune system is not successful in attacking the virus, it survives and spreads into the bloodstream, resulting in HFMD.

HFMD usually produces painful sores on the throat, mouth and tongue. Skin lesions may also appear on the hands, feet and sometimes the buttocks. These lesions are also painful and very contagious. Touching an HFMD sore and then touching the mouth can spread the infection. It may also spread from utensils and toys that came into contact with a sore.

However, HFMD is seldom serious and rarely requires medical treatment. The sores usually clear up within 10 days. In rare circumstances, HFMD can lead to complications in other parts of the body, including the lungs, heart and brain.

Hand, foot and mouth disease (HFMD) is a common viral infection that causes painful sores in the mouth and a rash with small blisters on the hands and feet. A vast majority of the time the disease affects children, though adults may become infected as well.

HFMD is often confused with foot-and-mouth disease, which is a highly infectious viral disease found in farm animals. However, these diseases are not related and are caused by different viruses. In addition, HFMD is not transmitted by animals to humans or vice versa.

Hand, foot and mouth disease is caused by members of a group of viruses known as enteroviruses, which are tiny viruses composed of ribonucleic acid (RNA) and protein. According to the U.S. Centers for Disease Control and Prevention (CDC), the enteroviruses cause an estimated 10 to 15 million or more infections a year in the United States.

HFMD is very contagious and spreads through direct contact with an infected person, usually through unwashed hands or contaminated surfaces or objects (e.g., utensils, telephone). A patient is most contagious during the first week of the illness. However, the infection is generally mild and nearly all patients recover without medical treatment in seven to 10 days.

The most common complication of HFMD is dehydration. The sores in the mouth and throat can make swallowing painful and difficult, causing some patients not to consume the necessary fluids. In addition, HFMD may pose some complications during the first three months (the first trimester) of pregnancy. Pregnant patients who develop the disease shortly before delivery are at risk for passing the virus to the newborn. Although most newborns with HFMD have mild symptoms, in rare cases they may develop a severe life-threatening infection involving many organ systems, including the heart and liver.

Other complications of HFMD are rare and may include:

• Aseptic meningitis. An infection resulting in inflammation of the membranes (meninges) and cerebrospinal fluid surrounding the brain and spinal cord. Aseptic or viral meningitis is usually mild and often resolves on its own in about 10 days.
  
  
• Pneumonia. Inflammation of the lungs caused by infection with a virus.
  
  
• Myocarditis. A rare viral infection resulting in inflammation of the heart.
  
  
• Encephalitis. A severe and potentially life-threatening disease that involves brain inflammation caused by a virus.

Prevalence of HFMD is seasonal in temperate climates, with outbreaks usually occurring in the summer and fall. In tropical climates, the disease occurs during all seasons. In recent years, major outbreaks of the viral infection with severe complications were reported in Malaysia and Taiwan.

Hand foot and mouth disease (HFMD) is caused by certain members from a group of viruses known as enteroviruses (tiny viruses composed of ribonucleic acid [RNA] and protein). Viruses included in the enterovirus group include coxsackie viruses, polioviruses and echoviruses. Infection with coxsackievirus A16 is the most frequent cause of HFMD. Other strains of coxsackievirus A and enterovirus 71 are also common causes of HFMD.

Epidemic HFMD viral infections are usually caused by specific types of enteroviruses. Infections usually occur as isolated events, but epidemics occur fairly regularly, approximately every 3 years. Cases of HFMD occur most often in the summer and early fall.

HFMD is very contagious and spreads through direct contact with the bodily fluids (e.g., saliva, nasal and throat discharge), fluid from the blistering skin sores and feces (stool) of an infected person. The virus can also spread when an infected person coughs or sneezes, spraying a mist of fluid containing viruses in the air.

Once the virus enters the body, usually via the mouth, it reproduces in the digestive tract. At this stage, the immune system normally prevents the infection from spreading, resulting in few or no symptoms. When the immune system is not successful in attacking the virus, it can survive and spread into the bloodstream, resulting in HFMD.

The usual incubation period (amount of time from infection to onset of symptoms) is between three to six days. A person is most contagious during the first week of the illness. However, HFMD is generally mild and nearly all patients recover without medical treatment in seven to 10 days.

People who have developed HFMD become immune to the virus that caused it. However, this does not mean they will not develop the condition again. It is possible to develop subsequent episodes of HFMD if a different member of the enterovirus group enters the body.

HFMD most commonly affects children and can spread rapidly wherever groups of children are in close contact, such as in schools and childcare settings. Although it can also affect adults, children are at increased risk for HFMD because their immune systems have not yet fully developed. They are also less likely than adults to have developed immunity as a result of previous exposure.

Additional risk factors for developing HFMD include:

• Direct contact with a person who has the disease or with contaminated surfaces or objects (e.g., utensils).
  
  
• Weakened immune system. People suffering from diseases that weaken the immune system, such as diabetes (high blood sugar levels), may be more prone to infection.
  
  
• Crowded conditions, especially in places where there is poor hygiene.

Patients with hand, foot and mouth disease (HFMD) may experience a fever followed by a sore throat and sometimes a decrease in appetite along with malaise (a general ill feeling). The following may also occur:

• One or two days after the onset of fever, painful red sores may develop in the throat, on the gums, on the inside of the cheeks and on the tongue.
  
  
• A rash may appear with small blisters on the palms of the hands and the soles of the feet, and may spread to the buttocks. The rash does not itch. However, the blisters are tender or painful when pressured is applied. The sores and rash typically heal spontaneously within 10 days.
  
  
• Other symptoms may include headache and irritability (in young children).

Generally, symptoms of HFMD are more severe in children than adults, although in most cases the disease has a mild course and patients rarely experience severe complications (e.g., pneumonia, encephalitis).

Patients are advised to seek medical attention if they experience the following symptoms:

• Pain in the neck, arms or legs
• High fever not reduced by over-the-counter medication
• Signs of dehydration, including:
  
• • Weight loss
  • Decreased or dark-colored urine
  • Dry skin and mucous membranes
  • Lethargy

Hand, foot and mouth disease (HFMD) is diagnosed by a physician based on a visual examination of the skin lesions and the patient's symptoms. A physician will perform a complete physical examination and compile a thorough medical history when making a diagnosis to help distinguish HFMD from other common causes of mouth sores (e.g., herpes). If a newborn is suspected of having the disease, a physician may refer the baby to the care of a neonatologist, a physician who specializes in the medical treatment of newborn infants.

Sometimes, a physician may obtain a sample of a bodily fluid from either a throat swab or stool specimen for analysis to determine which of the enteroviruses caused the illness. However, in general, no laboratory tests are necessary to diagnose HFMD.

Since HFMD is caused by a virus, treatment with antibiotics is not effective and is not indicated. Usually, no medical care is necessary to treat HFMD and most patients experience complete recovery in seven to 10 days. However, a new drug called pleconaril is currently undergoing clinical trials and has shown promise in treating severe cases of the viral infection.

Oftentimes, physicians may recommend the following for relief of symptoms:

• Over-the-counter medications to reduce fever and relieve headache. These include nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, or acetaminophen. However, aspirin should not be administered to children under age 12 because of the risk of developing a rare but serious condition called Reye’s Syndrome.
  
  
• Topical anesthetics to treat painful mouth sores (e.g., lidocaine, diphenhydramine).
  
  
• Salt-water mouth rinses to soothe the throat. This can be done by diluting half a teaspoon of salt into a glass of warm water.
  
  
• Plenty of fluids to prevent dehydration, a common complication of most diseases resulting in fever. Good choices include cold milk products, such as ice cream. Patients may also suck on popsicles and ice chips. Acidic beverages, such as fruit juices and sodas, should be avoided because they can irritate blisters in the throat, mouth or tongue.

Patients with HFMD should also restrict their activities and get plenty of rest until their symptoms subside.

The likelihood of becoming infected with hand, foot and mouth disease (HFMD) can be reduced by practicing the following:

• Washing hands. Careful hand washing is necessary to reduce the potential of spreading HFMD, especially after using the toilet or changing diapers, as well as before eating or preparing foods.
  
  
• Disinfecting common areas and/or objects (e.g., kitchen, utensils, toys, baby pacifiers). This is especially important since the virus can live on objects or surfaces for several days.
  
  
• Good personal hygiene. It is important that adults teach children to practice good hygiene (e.g., frequent hand washing and bathing). In addition, children should be told not to put their fingers, hands or any other objects into their mouths to avoid diseases. Children should also be taught not to share utensils.
  
  
• Avoiding contact with infected individuals. Because HFMD is very contagious, people should limit their exposure to infected individuals. It is also important for infected individuals to remain home during the illness, away from crowded public places (e.g., schools, daycare centers, supermarkets), until their physician advises them otherwise.

Preparing questions in advance can help parents to have more meaningful discussions with their child's physicians. Parents may wish to ask their child's doctor the following questions about hand, foot and mouth disease (HMFD):

1. Do my child’s symptoms indicate HFMD?
   
   
2. Does HMFD pose a danger to my child's overall health?
   
   
3. What are my child's treatment options?
   
   
4. When can I expect my child’s symptoms to subside?
   
   
5. How likely am I or other members of household to contract the disease?
   
   
6. How can I prevent the disease from spreading to the rest of my family?
   
   
7. Should I isolate my child from his or her siblings?
   
   
8. At what point will my child no longer be contagious?
   
   
9. How long will my child need to be out of school?
   
   
10. My child has HFMD and I am pregnant. Will this be harmful to my unborn child?