How long is a child with hand, foot, and mouth disease (HFMD) contagious and when is it safe for them to return to school?

Hand, Foot, and Mouth Disease: Contagious Period and Return to School Guidelines

Children with hand, foot, and mouth disease (HFMD) are typically contagious from 1-2 days before symptoms appear until all blisters have dried and crusted over, usually 7-10 days from symptom onset, and should not return to school until they are no longer contagious.

Understanding HFMD Transmission

HFMD is a highly contagious viral illness primarily caused by enteroviruses, particularly:

• Coxsackievirus A16 (CV-A16)
• Enterovirus 71 (EV-A71)
• Coxsackievirus A6 (CV-A6)
• Coxsackievirus A10 (CV-A10) 1, 2

The virus spreads through multiple routes:

• Direct contact with respiratory secretions, saliva, or fluid from blisters 3
• Fecal-oral transmission 1
• Contact with contaminated surfaces and objects (fomites) 1

Contagious Period

The contagious period for HFMD follows a specific timeline:

• Begins 1-2 days before symptoms appear 3
• Continues throughout the acute illness phase 1
• Extends until all blisters have dried and crusted over 1
• Generally lasts 7-10 days from symptom onset 1, 3

However, it's important to note that:

• Viral shedding can continue in stool for several weeks after symptoms resolve 3
• Some studies suggest patients should be considered potentially contagious for at least 10-14 days 3

When to Return to School

Children with HFMD should not return to school until:

• Fever has resolved without fever-reducing medications 3
• All blisters/vesicles have dried and crusted over 1
• At least 7 days have passed since symptom onset 3

Preventing Transmission

To prevent spreading HFMD to others:

• Practice thorough handwashing with soap and water (alcohol-based sanitizers alone are not sufficient) 3
• Avoid close contact with others during the contagious period 3
• Use separate towels and utensils 3
• Disinfect frequently touched surfaces and toys 1
• Properly dispose of tissues containing nasal secretions 3

Special Considerations

High-Risk Settings

Those in professions with high potential for transmission should be especially cautious:

• Healthcare workers should follow strict infection control protocols 3
• Childcare providers should be particularly vigilant about handwashing and disinfection 3

Complications

While HFMD is typically self-limiting, parents should be aware of potential complications:

• Rare neurological complications like meningitis or encephalitis 1, 4
• Dehydration from painful oral ulcers limiting fluid intake 1
• Secondary bacterial infections of skin lesions 1

Treatment

Treatment is supportive and focuses on:

• Maintaining adequate hydration 1
• Pain relief with acetaminophen or ibuprofen as needed 1
• Avoiding spicy, acidic, or hot foods that may irritate mouth ulcers 5

Common Pitfalls to Avoid

1. Returning to school too early: Children who return before the contagious period ends can trigger outbreaks 3

2. Relying only on fever resolution: Some parents may send children back to school once fever resolves, but the child remains contagious until all lesions have crusted 3

3. Inadequate hand hygiene: Using only alcohol-based sanitizers is insufficient; soap and water are more effective against enteroviruses 3

4. Overlooking environmental cleaning: Enteroviruses can remain viable on surfaces for up to 28 days 3

5. Assuming mild cases aren't contagious: Even mild cases with few lesions can transmit the virus effectively 6