Hand foot and mouth disease (HFMD) is a viral illness commonly affecting children below 10 years. Although it can affect teenagers and adults as well, this age group often has milder symptoms.
Adults rarely get this infection as they have been exposed to it in their childhood.
The most common causative organism is Coxsackie virus A 16. Other causes are coxsackie B virus and enterovirus 71 strains.
How long do the symptoms take to appear?
The symptoms of the hand, foot and mouth disease usually takes between 3 and 7 days to appear. This is called the incubation period.
The disease lasts for around a week to 10 days and often resolves completely on its own without treatment.
There are children who catch the infection but may not show any symptoms of the infection.
Early symptoms of hand, foot and mouth disease
Early symptoms of the condition include (1-8):
- Fever – High fever as high as 40º C (104º F) may be seen in most children. The fevers are typical of viral illness with high and regularly timed peaks and resolution of temperature to normal between two peaks.
- Headache – Small children often experience headache due to HFMD
- As will most viral illnesses children with HFMD experience loss of appetite.
- There is a sore throat. The throat is often painful. On examination the throat shows red spots over the throat, tonsils, mouth and tongue. These may be painful and may make swallowing difficult.
- Enterovirus 71 can cause vomiting in some patients.
Later symptoms of hand, foot and mouth disease
Later symptoms of the condition include (1-8):
- After the initial day or two of the infection many children develop red spots in the mouth that progress to ulcers. These worsen and are present in the mouth, tongue, tonsils, over gums and insides of the cheeks and throat. These are extremely painful and make it difficult to eat, drink or swallow. The ulcers typically appear yellow with red haloes around them. Children aged under 5 years tend to have worse symptoms than older children.
- Nearly 75% of the infected patients develop characteristic rash or blisters over:
- the soles of the feet
- palms of the hand
- between fingers and toes
- diaper area
These blisters are painful and may be tender if touched upon or pressed. They may itch initially but the rashes in most cases become non-itchy.
The spots are flat or raised, sometimes with blisters, and are smaller than chickenpox sores. This rash is a characteristic feature of the infection that leads the condition its name.
The rashes begin as red spots and rapidly progress to grey blisters with a red and raw base. Trunk and thighs may also be affected. The rash lasts about 3 to 6 days. The fluids in the blister is usually infective.
Complications of hand, foot and mouth disease
Complications of HFMD include (5):
- High fever in children leading to dehydration
- High fever may lead to febrile seizures or convulsions in very young children
- Infections of the lesions by bacteria or superimposed infections
- Viral (aseptic) meningitis is a rare complication. Symptoms of viral meningitis or brain infection by the virus include headache, stiff neck, and fever. There may be swelling of the brain. These patients usually need hospitalization.
Reviewed by April Cashin-Garbutt, BA Hons (Cantab)