Hand, foot and mouth disease - Complications of hand, foot and mouth disease

Hand, foot and mouth disease is usually a mild condition that clears up on its own without the need for treatment.

Complications are rare, but they could include those described below.

Dehydration

The sores that develop in your throat and mouth may make drinking and swallowing difficult, which can lead to dehydration. It is important for your child (or yourself) to drink plenty of fluids. Encourage your child to drink water and milk rather than acidic drinks like fruit juice.

It may be easier if you encourage your child to drink small amounts frequently rather than attempting to drink a large amount.

Contact your GP for advice if your child is unable or unwilling to drink any fluids, or if they are showing signs of dehydration, including:

dry, wrinkled skin that sags slowly into position when pinched
an inability to urinate, or not passing urine for eight hours
irritability
sunken eyes
your child appears unusually tired and listless
(in babies) a sunken soft spot (fontanelle) on their head

Mild cases of dehydration can be treated using rehydration solutions, which are available from most pharmacists.

More severe cases may require treatment in hospital.

Secondary infection

There is also a risk that the sores on the skin can become infected, especially if the sores are scratched.

Symptoms of skin infection include:

pain, redness, swelling and a feeling of heat at the site of the infection
a discharge of pus or liquid from the skin

Contact your GP if you think your child has a skin infection, as they may need to be treated with antibiotic cream or tablets.

Viral meningitis

In rare cases, hand, foot and mouth disease can lead to viral meningitis. Viral meningitis is an infection of the membranes that cover the brain and spinal cord (the meninges).

Viral meningitis is less severe than bacterial meningitis and does not pose a serious threat to health.

Most children will make a full recovery within two weeks.

Symptoms include:

a high temperature (fever) of or above 38°C (100.4°F)
drowsiness
headache
neck stiffness
dislike of bright lights

There is no specific treatment for viral meningitis other than using painkillers to help relieve symptoms.

Encephalitis

The most serious, but rarest, complication of hand, foot and mouth disease is encephalitis – an infection that causes the brain tissue to swell and become inflamed.

It can cause brain damage and is potentially life threatening.

Early signs of encephalitis are flu-like symptoms, which can develop in a few hours or over a few days. Other symptoms include:

being sick
lethargy, drowsiness or confusion
jerking of the limbs
weakness or paralysis of the limbs
dislike of bright lights
other specific neurological symptoms

If you develop encephalitis, you will need to be admitted to hospital.

Most reported cases of encephalitis related to hand, foot and mouth disease have occurred during mass outbreaks of cases (epidemics) caused by enterovirus 71.

So far, these epidemics have only occurred in Asian countries, such as China and Taiwan.