Hand, foot and mouth disease

Definition

Hand, foot and mouth disease (HFMD) is a contagious viral illness that primarily affects infants and young children, though it can occur in adults. It is characterized by fever, oral ulcers, and a vesicular rash on the hands, feet, and sometimes the buttocks and genital area.

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Etiology

• Common causative viruses:

  • Coxsackievirus A16 – most frequent cause worldwide

  • Enterovirus 71 – associated with more severe disease and neurological complications

  • Other coxsackievirus and enterovirus serotypes

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Transmission

• Person-to-person via:

  • Respiratory droplets

  • Direct contact with blister fluid or feces of infected individuals

• Incubation period: 3–7 days

• Most contagious in the first week, but virus can be shed for weeks in stools

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Pathophysiology

After entry through the mouth or respiratory tract, the virus replicates in lymphoid tissue of the oropharynx and small intestine, spreads via the bloodstream, and targets the skin and oral mucosa, leading to the characteristic rash and mouth lesions.

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Clinical Features

Prodromal phase (1–2 days):

• Low-grade fever

• Malaise, irritability

• Sore throat, reduced appetite

Rash and oral lesions:

• Painful vesicles/ulcers in the mouth (tongue, buccal mucosa, palate) – cause drooling, refusal to eat or drink

• Vesicular rash on palms and soles; sometimes on buttocks, knees, elbows

• Rash: small red macules → vesicles with erythematous halo; non-pruritic, non-painful on skin (painful in mouth)

Duration: Symptoms usually resolve in 7–10 days

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Complications (rare, more likely with Enterovirus 71)

• Viral meningitis

• Encephalitis

• Acute flaccid paralysis

• Pulmonary edema or hemorrhage (severe EV71 outbreaks in Asia)

• Dehydration from reduced oral intake due to painful mouth ulcers

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Diagnosis

• Clinical diagnosis based on characteristic oral and skin lesions plus fever in a child with compatible exposure history

• Laboratory confirmation (PCR, viral culture) rarely needed, reserved for severe or atypical cases

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Management

No specific antiviral treatment – supportive care is the mainstay.

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Supportive Care

1. Fever and pain control

   • Paracetamol: 10–15 mg/kg orally every 4–6 hours (max 60 mg/kg/day in children)

   • Ibuprofen: 5–10 mg/kg orally every 6–8 hours (max 40 mg/kg/day) for children >6 months

2. Oral discomfort relief

   • Cold fluids, ice lollies, soft foods

   • Avoid acidic or spicy foods

   • Topical oral anesthetics (e.g., lidocaine gel) – with caution and under supervision, especially in young children

3. Hydration

   • Encourage oral fluids; oral rehydration solution if reduced intake

   • Hospital admission if unable to maintain hydration

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Infection Control

• Hand hygiene after diaper changes or contact with secretions

• Disinfect contaminated surfaces and toys

• Exclude child from daycare/school until fever subsides and child feels well (skin lesions need not be fully healed)

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Prevention

• No licensed vaccine available for most strains except for EV71 in some countries

• Handwashing, respiratory etiquette, and environmental cleaning reduce transmission

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Prognosis

• Usually mild and self-limiting, full recovery expected in 7–10 days

• Severe complications are rare but require urgent medical attention

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When to Seek Medical Help Immediately

• Signs of dehydration (dry mouth, decreased urine output, lethargy)

• Persistent high fever >39 °C

• Neurological symptoms (drowsiness, confusion, seizures)

• Shortness of breath or chest pain