Hand, foot, and mouth disease (HFMD) is a common viral infection that causes fever, painful mouth sores, and a blister-like rash on the hands and feet. It primarily affects children under 5, though adults can catch it too. The illness is usually mild and resolves on its own within 7 to 10 days, but the mouth sores can make eating and drinking genuinely miserable for a few days.
What Causes It
HFMD is caused by a group of viruses called enteroviruses. The most common culprit is coxsackievirus A16, which tends to produce the classic, milder form of the illness. A different strain, enterovirus A71, is less common but more concerning because it can occasionally lead to serious neurological complications like meningitis or encephalitis. Three vaccines targeting enterovirus A71 have been licensed in China, but no HFMD vaccine is available or approved for use in the United States, Europe, or most other countries.
A third strain worth knowing about is coxsackievirus A6, which causes an atypical version of the disease. Instead of the usual small blisters limited to hands, feet, and mouth, A6 can produce a widespread rash covering the arms, legs, trunk, buttocks, and genital area. It sometimes looks more like chickenpox than classic HFMD, which can confuse both parents and doctors. Some people with A6 infections also lose a fingernail or toenail weeks after the illness clears.
How Symptoms Develop
Symptoms typically appear 3 to 6 days after exposure. The illness usually starts with a fever and sore throat. One or two days later, painful blister-like sores develop in the front of the mouth or throat. Around the same time, a rash appears on the palms of the hands and soles of the feet, and sometimes on the buttocks. The rash may look like flat red spots or raised blisters.
The mouth sores are usually the worst part. They make swallowing painful, which is especially hard for toddlers and infants who can’t understand why eating hurts. Some children stop drinking enough fluids, so dehydration becomes the main practical concern during the illness.
How It Spreads
HFMD is highly contagious. The virus travels through respiratory droplets when someone coughs, sneezes, or talks. It also spreads through direct contact with blister fluid, saliva, nasal mucus, and stool. Changing a sick child’s diaper and then touching your face is a common route. Contaminated surfaces like doorknobs and toys can harbor the virus too.
People are most contagious during the first week of illness, but the virus can continue shedding in stool for days or even weeks after symptoms disappear. Some people spread the virus without ever developing symptoms themselves. In rare cases, the virus can spread through improperly chlorinated swimming pools contaminated with an infected person’s stool.
Adults Can Get It Too
HFMD isn’t strictly a childhood illness. Adults, particularly parents and caregivers of sick children, can catch it. The symptom pattern is the same: fever, mouth sores, and a rash on the hands and feet. Adults sometimes experience more intense pain from the mouth sores and may feel generally sicker, though serious complications remain rare. Because many adults were exposed to these viruses in childhood, some have partial immunity that reduces their risk or severity.
Managing Symptoms at Home
There’s no antiviral treatment for HFMD. The illness runs its course, and care focuses on keeping your child comfortable and hydrated. Over-the-counter pain relievers appropriate for your child’s age can help with fever and soreness. Topical oral anesthetics, available as gels or sprays, can numb mouth sores temporarily, but lozenges shouldn’t be given to children under 4 due to choking risk. Throat sprays containing benzocaine should not be used for children under 2 because the ingredient can cause a rare but serious blood condition.
Cold foods are your best friend during the worst days. Ice pops, ice chips, ice cream, and sherbet all soothe mouth pain and provide fluids at the same time. Soft foods that don’t require much chewing are easier to tolerate. Avoid anything acidic: citrus fruits, fruit juice, and soda will sting open sores and make your child refuse to eat entirely. Older children who can rinse without swallowing may find warm salt water soothing if they swish it several times a day.
The single most important thing is keeping fluids going in. Small, frequent sips of cool water or milk are better than trying to get a child to drink a full cup at once. Watch for signs of dehydration: fewer wet diapers, dry lips, no tears when crying, or unusual sleepiness.
When Children Can Return to School
The CDC says children can go back to childcare or school as long as they have no fever, feel well enough to participate in class, and don’t have uncontrolled drooling from mouth sores. Because the virus can shed for weeks after recovery, waiting until every trace of contagiousness is gone isn’t practical. Local health departments may impose stricter rules during outbreaks, so it’s worth checking if your child’s daycare has its own policy.
Preventing the Spread
Frequent handwashing is the most effective prevention measure, especially after diaper changes, after using the bathroom, and before preparing food. Clean and disinfect frequently touched surfaces with a bleach solution of 1 to 3 tablespoons of household bleach per quart of water. Avoid close contact like kissing, hugging, or sharing utensils with someone who’s sick. Because the virus lives in stool long after symptoms fade, careful hand hygiene after diaper changes should continue for several weeks after a child recovers.
Rare but Serious Complications
The vast majority of HFMD cases resolve without any lasting effects. Rare complications are almost exclusively linked to enterovirus A71 rather than the more common strains. In a small number of cases, this strain can cause viral meningitis (inflammation of the membranes around the brain and spinal cord) or encephalitis (inflammation of the brain itself). These complications tend to appear in children under 5, typically showing up 3 to 5 days after the initial fever and respiratory or gastrointestinal symptoms.
Warning signs of neurological involvement include unusual drowsiness or lethargy, difficulty walking or unsteadiness, persistent vomiting, and a very high fever that doesn’t respond to medication. These symptoms are uncommon, but they require immediate medical attention.