Does a child with Hand, Foot, and Mouth Disease (HFMD) still pose a risk to others after having blisters for 2-3 days?

Risk of Transmission of Hand, Foot, and Mouth Disease After 2-3 Days of Blisters

Children with Hand, Foot, and Mouth Disease (HFMD) pose limited risk to others after having blisters for 2-3 days, as the disease is most contagious during the first week of illness, particularly before the appearance of blisters.

Understanding HFMD Transmission

HFMD is a highly contagious viral illness primarily affecting young children under 5 years of age. The disease is characterized by:

• Typical manifestations including oral sores and rashes on hands and feet 1
• Caused by various enteroviruses, most commonly coxsackievirus A16, enterovirus A71, and increasingly coxsackievirus A6 1, 2
• Symptoms that typically resolve spontaneously within a few days without complications 1

Transmission Timeline and Contagiousness

The contagious period of HFMD follows a predictable pattern:

• Most patients seek medical care during the first 2-4 days of illness, after an incubation period of approximately 5-10 days after exposure 3
• The disease is most contagious during the first week of illness, particularly during the prodromal phase (fever, sore throat) before the appearance of blisters 4
• By the time blisters have been present for 2-3 days, viral shedding typically decreases significantly 1
• Blisters should generally be left intact if possible as this may help prevent secondary bacterial infection 3

Clinical Course and Resolution

The typical progression of HFMD includes:

• Initial symptoms of low-grade fever, malaise, and mild sore throat 5, 6
• Development of characteristic vesicular rash on hands, feet, and in the mouth 4
• Rash typically resolves within 7 days without treatment or complications 5
• Most infections are asymptomatic; symptomatic cases typically present with mild febrile illness 4

Infection Control Considerations

When managing a child with HFMD, consider these infection control principles:

• Standard precautions should be followed, including performing hand hygiene before and after every patient contact 3
• While gloves are generally recommended when contact with body fluids is anticipated, they are not required for routine care of children with resolving HFMD lesions 3
• After 2-3 days of blisters, if the child is improving clinically with decreasing fever and no new lesion formation, the risk of transmission is significantly reduced 1, 5
• Children can generally return to school or daycare once fever has resolved and mouth sores have decreased in number and are no longer causing drooling 4

Special Considerations

• HFMD can occasionally recur in the same child, though this is relatively rare 5
• Some children may experience nail dystrophies (e.g., Beau's lines or nail shedding) weeks after the initial infection 4
• While most cases resolve without complications, severe cases can lead to neurological complications, though these are uncommon 1, 2

Practical Recommendations

• By day 3-4 of visible blisters, if the child is clinically improving and has no fever, they pose minimal risk to others 1, 4
• Good hand hygiene remains important even as the disease resolves 3
• Avoid close contact activities and sharing of utensils until all blisters have dried 6
• The risk of transmission is significantly reduced once blisters begin to crust over 5