Hand, foot, and mouth disease (HFMD) is caused by different types of virus called enterovirus, and the most common ones are coxsackie virus type A16, A5, A9, A10, B1 and B3, human enterovirus 71 (HEV71), and herpes simplex viruses (HSV).
The virus is spread from person to person through direct contact with nose and throat discharges, blister fluid, and faeces. Therefore coughing and sneezing can spread the virus from the infected person to healthy persons.
When the virus enters the body, it multiplies at the contact site such as in the throat, surrounding lymphatic nodes, stomach and intestines. Then it gets into the blood and flows to other parts of the body such as mouth and the skin.
The symptoms of HFMD start to show after around 72 hours of the incubation period. The virus is expelled out of the human body through stools following six-eight weeks.
HFMD is a common worldwide disease and is more widespread in summer and early spring. In tropical countries, it can be widespread in any season.
In Thailand, it is more commonly found in rainy season, and usually affects children under five years of age. The most common breeding grounds for the virus are places with lots of children such as nurseries or kindergartens.
The symptoms of HFMD include low-grade fever, loss of appetite, stomachache and pain in the mouth. Soon, blisters develop in the mouth and on the skin, commonly at the hands and feet, and sometimes at buttocks. The typical blisters are yellow with bright red borders. They usually appear in the mouth such on the tongue, palate, velum, tonsils or gums. Skin rashes also develop at the back of the hands and feet, or at the palms. They might or might not be itchy. These rashes start of as red rashes and quickly develop into raised red spots, some with blisters. Usually, the rashes will go away within a week.
Skin infection is a common complication that follows. Symptoms, however, can vary. Rarely, there are complications involving the blood and nervous system that may result in death.
There is no specific treatment for HFMD. The treatment available is just for symptom relief. Medication is prescribed according to the symptoms, such as fever, and oral anesthetic to help relieve the pain of mouth sores.
For infected children, it is very important to keep them hydrated. You can assess the hydration status by checking the pulse, skin elasticity, mouth and eye hydration, tears when they cry, and urination frequency. Infected children should be separated from others to avoid spreading of the virus. They should go to see the doctor as soon as possible, and rest at home for at least six days until the symptoms have disappeared. If infected children develop unusual symptoms like high fever, vomiting or difficult breathing, they need to go to the hospital immediately.
To prevent the virus from spreading, avoid taking infected children to crowded places, such as playgrounds, swimming pools, markets and department stores. It is better to stay in a place with good ventilation. They should be told to cover their mouth and nose when coughing and sneezing. The person who takes care of the infected child must practise good hygiene and wash their hands often, especially after touching the child's mucus, saliva or stool.
Schools, daycare centres and other public places with infected kids should close temporarily or at least five days. The place must be cleaned and disinfected properly. School management may contact health authorities for advice and assistance, while informing the parents and children about safety measures and how to prevent the spreading of the disease, such as by keeping the hands clean and avoid using personal items with infected person.
Disinfection is needed also for eating utensils and toilets by using bleach (20 ml/litre of water) or disinfectants followed by a washdown with water. Air-conditioning should not be used when the virus is spreading. Instead keep the place well ventilated.
Information is provided by the Bangkok Health Research Centre, Bangkok Hospital.