Hand, Foot, and Mouth Disease (HFMD) is a common, highly contagious viral illness that primarily affects infants and young children. This infection is caused by viruses belonging to the Enterovirus genus, with Coxsackievirus A16 and Enterovirus 71 being the most frequent culprits. HFMD is characterized by a distinctive rash that appears on the hands and feet, along with painful sores that develop in the mouth. The virus spreads easily through close personal contact, respiratory droplets, and contact with contaminated surfaces or stool.
The Typical Timeline of HFMD Lesions
The rash and sores typically emerge one or two days after the initial systemic symptoms, such as fever and malaise, have begun. These lesions first appear as small, flat, reddish spots that evolve quickly into fluid-filled blisters, or vesicles. The duration for the lesions to clear is generally between seven and ten days from their initial appearance.
The most distinguishing feature of the illness is the presence of painful ulcers within the mouth, often appearing on the tongue, gums, and the inside of the cheeks. These oral sores cause the peak of discomfort, usually occurring within the first three to five days of their appearance. Swallowing becomes difficult due to this pain, which can lead to a temporary refusal to eat or drink.
On the skin, the lesions are most commonly found on the palms of the hands and the soles of the feet, but they may also appear on the buttocks, knees, and elbows. These skin lesions are typically non-itchy and can look like flat spots or small, raised bumps that may blister. The fluid inside these blisters contains the infectious virus, so it is important to avoid breaking them open. The skin blisters will gradually dry up and crust over, eventually resolving without scarring. While the mouth sores often heal quickly, the spots on the hands and feet might linger for the full ten-day period before completely fading.
Full Progression of the Illness
The journey of HFMD begins silently with an incubation period that lasts between three and six days after exposure to the virus. The first signs of infection mark the prodromal stage, beginning with non-specific, flu-like symptoms such as a low-grade fever, sore throat, and a general feeling of being unwell.
The acute phase of the illness, where the characteristic lesions develop, typically lasts for seven to ten days in total. The fever usually subsides first, often within three to four days, even as the mouth sores and rash are still present. The disease is most easily spread during the first week of infection, when the symptoms are at their peak and the blister fluid contains high concentrations of the virus.
Although the physical symptoms resolve, the individual can continue to shed the virus for an extended period, sometimes for weeks, primarily through their stool. This means a person may still be contagious even after all visible sores have healed and they feel completely better. A child can typically return to group settings once the fever is gone and mouth sores are manageable.
Strategies for Pain Relief and Comfort
Since there is no specific antiviral treatment for HFMD, managing the discomfort and symptoms is the primary focus of care. Over-the-counter pain relievers, such as acetaminophen or ibuprofen, can be administered to help reduce fever and alleviate the pain associated with the mouth sores. Aspirin should not be given to children or teenagers because of the risk of Reye’s syndrome.
Hydration Management
Hydration is a paramount concern, especially when painful mouth ulcers make swallowing difficult. Offering cold liquids, such as water, milk, or electrolyte solutions, can be soothing and helps maintain fluid balance. Ice pops and smoothies can also serve a dual purpose by providing both hydration and a numbing effect on the irritated areas.
Dietary Modifications
Dietary modifications can significantly improve comfort during the acute phase of the illness. Soft, bland foods like yogurt, pudding, and pasta are generally better tolerated than items that require significant chewing. Acidic, spicy, or salty foods, including citrus juices, should be avoided as they can irritate the oral sores and increase pain.
Identifying Complications and When to Consult a Physician
Hand, Foot, and Mouth Disease is typically a mild and self-limiting condition, but caregivers should monitor for signs that indicate a need for medical attention. The most common complication is dehydration, which occurs when mouth pain prevents a person from drinking enough fluids.
Signs of dehydration include:
- Reduced urination
- Dry lips and mouth
- Excessive lethargy
- A lack of tears when crying
A physician should also be consulted if the fever persists for longer than three days or if the symptoms are severe and do not begin to improve after ten days. Although rare, certain severe symptoms could suggest the development of neurological complications, such as viral meningitis or encephalitis.
These warning signs include:
- A persistent, severe headache
- Neck stiffness
- Extreme irritability
- Seizures
- Unusual disorientation
Parents of infants under six months old or children with weakened immune systems should seek medical advice promptly, as these groups are at a higher risk for complications. While secondary bacterial infection of the skin lesions is uncommon, increasing redness, swelling, or pus around a blister warrants an evaluation.