Hand, Foot, and Mouth Disease (HFMD)

Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management | References

Definition

Hand, Foot, and Mouth Disease (HFMD) is a common viral infection that mainly affects children under the age of 10. It is characterised by fever, mouth sores, and a rash on the hands, feet, and sometimes buttocks. HFMD is typically a mild, self-limiting illness that resolves within 7 to 10 days. It is caused by a group of viruses known as enteroviruses, with Coxsackievirus A16 and Enterovirus 71 being the most common causes.

Aetiology

HFMD is primarily caused by the following viruses:

• Coxsackievirus A16: The most common cause of HFMD, typically associated with mild cases.
• Enterovirus 71: Can cause more severe cases, sometimes leading to neurological complications such as viral meningitis or encephalitis.
• Other enteroviruses: While less common, other strains of enterovirus can also cause HFMD.

Pathophysiology

HFMD is spread through direct contact with bodily fluids, such as saliva, mucus, or faeces of an infected person. The virus enters the body through the mouth or respiratory tract and replicates in the gastrointestinal tract before spreading to other parts of the body. It primarily affects the skin and mucous membranes, leading to the characteristic sores in the mouth and the rash on the hands and feet.

In rare cases, the virus can spread to the central nervous system, causing complications such as viral meningitis, encephalitis, or paralysis.

Risk Factors

• Age: HFMD primarily affects children under the age of 10, particularly those under 5 years old.
• Close contact: Children in childcare settings or schools are more likely to contract the virus due to close contact with other children.
• Season: Outbreaks are more common during warmer months, such as late spring, summer, and early autumn.
• Poor hygiene: HFMD can spread easily in environments where handwashing and hygiene practices are inadequate.
• Weakened immune system: Children with a weakened immune system are at higher risk of more severe illness.

Signs and Symptoms

The signs and symptoms of HFMD typically develop 3 to 6 days after exposure to the virus. Common symptoms include:

• Fever: A low-grade fever is often the first symptom, lasting 1-2 days.
• Mouth sores: Painful red sores or blisters can develop on the tongue, gums, and inside of the cheeks, making it difficult for the child to eat or drink.
• Skin rash: A red, non-itchy rash with small blisters may appear on the hands, feet, and buttocks. The rash may not be present in all cases.
• General malaise: The child may experience a loss of appetite, irritability, and tiredness.
• Sore throat: Accompanying the mouth sores, the child may also have a sore throat.
• Dehydration: Due to mouth pain, children may avoid drinking, leading to dehydration in some cases.

Investigations

HFMD is usually diagnosed based on clinical presentation, including the characteristic rash and mouth sores. Investigations are rarely needed but may include:

• Clinical examination: A healthcare professional will check for the typical signs of HFMD, such as the rash on the hands, feet, and mouth.
• Throat swab or stool sample: In cases where the diagnosis is uncertain or complications are suspected, a throat swab or stool sample may be tested for the presence of the virus.
• Blood tests: In rare severe cases, blood tests may be performed to rule out other causes or complications.

Management

HFMD is a self-limiting illness, meaning it usually resolves on its own within 7 to 10 days. Management is mainly supportive to relieve symptoms:

Supportive Care:

• Pain relief: Paracetamol or ibuprofen can be used to reduce fever and alleviate the pain caused by mouth sores.
• Hydration: Encourage the child to drink plenty of fluids to prevent dehydration, particularly if they are avoiding food due to mouth pain. Cold fluids, ice lollies, or milk can help soothe sore throats.
• Soft foods: Offer soft, bland foods that are easy to swallow, such as yoghurt, soups, or mashed vegetables, to minimise discomfort during eating.

Preventing Spread:

• Good hand hygiene: Encourage regular handwashing, especially after using the toilet or changing nappies, to prevent the spread of the virus.
• Avoid close contact: Children with HFMD should be kept away from school or nursery until their fever has subsided, and any mouth sores and rashes have started to heal.
• Clean surfaces: Disinfect surfaces that have come into contact with an infected child, such as toys, to prevent the spread of the virus.

When to Seek Medical Attention:

Parents should seek medical advice if their child:

• Has symptoms that last longer than 10 days.
• Is unable to drink or shows signs of dehydration (e.g., dry mouth, reduced urine output).
• Develops a high fever that doesn’t improve with medication.
• Appears drowsy, confused, or has difficulty breathing.
• Shows signs of severe complications, such as persistent vomiting or seizures.

References

1. NHS (2023). Hand, Foot, and Mouth Disease: Causes and Treatments. Available at: NHS Website
2. NICE (2024). Hand, Foot, and Mouth Disease: Clinical Management Guidelines. Available at: NICE Guidance
3. British Medical Journal (BMJ) (2022). Paediatric Infectious Diseases: Hand, Foot, and Mouth Disease. Available at: BMJ