What doctors wish patients knew about hand, foot and mouth disease

Tiny hands, little feet and smiles turned upside down—parents across the country are on alert as a familiar yet frustrating visitor makes its seasonal rounds: hand, foot and mouth disease. Often striking in clusters at day cares and playgrounds, this common childhood virus—with more than 200,000 cases in the U.S. each year—is as contagious as it is uncomfortable, with telltale red spots, blisters and fevers that keep kids and their caregivers stuck at home. But knowing what to do and how to prevent hand, foot and mouth disease is key. 

The AMA’s What Doctors Wish Patients Knew™ series gives physicians a platform to share what they want patients to understand about today’s health care headlines.

In this installment, Terry Yen, MD, a pediatrician and chief medical officer at Texas Children’s Urgent Care, discusses what to know about hand, foot and mouth disease.

Texas Children’s Urgent Care is part of Texas Children’s Pediatrics, which is a member of the AMA Health System Program that provides enterprise solutions to equip leadership, physicians and care teams with resources to help drive the future of medicine.

“Hand, foot and mouth disease is a common infection that causes sores in and around the mouth,” said Dr. Yen, noting that the sores and rash are “often in a characteristic pattern on the hands, feet and even the buttocks, hence the name hand, foot and mouth disease.”

“It most often affects young children, but older children and adults can certainly get it too. The adults who get it tend to get a milder version of it,” he said. “There’s also a related infection called herpangina, which causes just the sores in the mouth and throat.”

“As for what causes it, like many other common infections in children, hand, foot and mouth disease is caused by viruses,” Dr. Yen explained. That is why “antibiotics are not usually effective at treating this illness.”

“The most common viruses causing this particular infection are called coxsackie viruses, which are part of a larger family of viruses called enteroviruses,” he said.

The rash associated with hand, foot and mouth disease “typically looks like small, red spots or bumps which often turn into small water-filled blisters called vesicles,” Dr. Yen said. “Sometimes those small water-filled blisters can rupture and become shallow ulcers as well, especially in the mouth, which can be painful.” 

“That’s probably the most concerning of symptoms because in young children the sores in the mouth can be quite painful,” he added. “The ones that are actually on the skin don’t always cause symptoms. They can be concerning to look at, but in terms of additional symptoms, they don’t typically itch.”

“If they have them all over their hands and feet, especially if there are open or ruptured little blisters, then sometimes they report pain in those areas as well,” Dr. Yen said. 

“Enteroviruses in general are more active in the summer and fall months, but really we can see sporadic cases and even outbreaks year-round, especially in the winter months,” Dr. Yen said. “But when you talk about the classic time of year to expect enterovirus infections and specifically hand, foot and mouth disease, summer and fall are typically when this occurs.”

“In Texas now, we’re monitoring for how prevalent the infection is in the area and what we certainly have seen is a typical summer and fall peak this year in Texas as well,” he said.

“With hand, foot and mouth disease, it’s often the sore throat or mouth pain, along with the emergence of the rash,” Dr. Yen said. “Like other viral infections, you can occasionally get high fevers with this as well. But with classic hand, foot and mouth disease, high fevers are not quite as common. It’s typically more low-grade fever.”

“Common symptoms of hand, foot and mouth disease can also be nonspecific things that you’ll see with other illnesses such as cough or congestion or even some vomiting or diarrhea,” he said. “Those can make the picture a little bit more confusing if there’s a lot of those symptoms also going on.

“In fact, with the cough and congestion, some people refer to these kinds of infections with enteroviruses the ‘summer flu’ because it can cause the same kind of respiratory symptoms,” Dr. Yen added.

“The virus itself can live in the body fluids of somebody who is infected,” Dr. Yen said. “So, we talk about mucus from the nose such as a runny nose, infected saliva and then even fluid from the skin sores—those small water-filled blisters.

“If they pop open, that fluid itself can also be infectious. And then occasionally the virus can be passed in the bowel movements as well,” he added. “So, it’s important to try to prevent contact with those body fluids with someone who has the infection.” 

“Almost all cases of hand, foot and mouth disease are diagnosed visually or clinically,” Dr. Yen said, noting “you’re putting the clinical picture together, which means looking at the symptoms, looking for the characteristic rash and the pattern of the rash is often helpful in terms of where it’s occurring on the body.

“Occasionally, with more severe infections you’ll see it spread a little bit to other parts of the body, but when it has the most prominent appearance of the hands, the feet and the mouth, that’s pretty telling as to what it is,” he added. “As for testing, there’s not usually a test done. If you get technical, there is specific viral testing you could do on body fluids to try to find a specific virus, but it’s almost never done because it’s not necessary and it doesn’t really add anything in terms of your diagnosis or treatment.”

When a child has hand, foot and mouth disease, households are at risk because other family members can get sick too, so it is important to “always take special precautions if there are people with any concerning conditions or high-risk conditions that live in the household as well,” Dr. Yen said. “But day cares and schools are probably the most frequent areas for these types of infections to spread.

“Most of the common illnesses we see in children, as soon as they go back to school, we see a rise in these types of illnesses being transmitted from one to another,” he added. 

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When it comes to treating hand, foot and mouth disease, the focus is on treating the symptoms, which “we call supportive care,” Dr. Yen said, explaining that “what you’re doing is treating the symptoms of pain or fever to keep the child comfortable so they don’t get complications.”

“If you keep your child comfortable, as a viral infection it’s going to be what we call self-limited, which means it’s going to run its course and it should go away on its own,” he said. “In terms of severity, it really depends on how the child’s responding to their symptoms—some kids manage better than others and some you need to treat the symptoms a little bit more aggressively.”

For example, “symptoms such as fever can cause kids to be even more uncomfortable than they already are and so you should be giving your typical over-the-counter medications like Tylenol or ibuprofen to reduce the fever. Those medications can treat the pain in many instances as well,” Dr. Yen said. “And occasionally some physicians will recommend using some type of mouthwashes to help soothe the pain, usually with some sort of antacid in it. 

“That can help them drink better, but if they’re not drinking well, then they start to get dehydrated and that’s when they might need more medical attention,” he added.

With hand, foot and mouth disease, “you get worried about children, especially younger children, who are not eating or drinking well becoming dehydrated. That would be a concern,” Dr. Yen warned. That is why it is important to “get children to drink more and help make them comfortable by treating the fevers and the pain.”

“If their physician recommended using some type of mouthwash to help with the mouth pain, especially for the young children such as the infants, that might help as needed as well,” he said. “Sometimes you can even apply that directly onto the mouth sores with a cotton swab and it may make them feel better and be more willing to drink. 

“But the biggest support they can provide is preventing dehydration, so drinking lots of fluids such as cold drinks, popsicles, slushies and milkshakes,” Dr. Yen added. “The liquids are always more important than solid foods in these circumstances.”

The mouth sores can also make it difficult to eat food because of the pain when swallowing. That is when “soft foods are better than crunchy foods,” Dr. Yen said. “Examples of soft food to eat are mashed potatoes, macaroni and cheese because those kinds of things don’t require a lot of chewing.”

It is also important to try “to avoid things such as salty and spicy foods, citrus and anything that might be irritating to the mouth or cause even more discomfort,” he explained. 

For the rash and sores experienced, “you don’t have to do much with them. They can be left open for the most part,” Dr. Yen said, noting that “I did mention that the fluid can be infectious if they burst open, but they usually dry up pretty quickly.

“So, it’s not necessary to try to cover them all up. Just keep them open. If they’re going to rupture, they’re going to rupture on their own,” he added. “And if they have a lot of those blisters, they shouldn’t be returning to day care or school.”

“We hear most routine infections are going to take seven to 10 days for recovery. Most children improve—particularly with the mouth sores—within about three to five days,” Dr. Yen said, noting that the “average is three to five days and then occasionally we’ll get a little bit more of a prolonged course with some of the sores and the rash lingering for up to a week or a little bit longer.”

For returning to school or day care, “it depends. It is typically recommended that they can return after they are fever free, first of all. So, ideally fever free for about 24 hours,” he said. “It’s also important that if the child, especially younger kids, have uncontrolled drooling because of the pain or they have open sores, especially a lot of open sores, it’s probably better not to have them return to school or day care until those symptoms have resolved.”

“Unfortunately, with hand, foot and mouth disease, you don’t develop immunity since this is a family of viruses that can cause this,” Dr. Yen said. “So, because there are various types of viruses that can cause these symptoms, just getting it once does not mean that you’re fully immune.”

However, “for all viral illnesses most of us start developing milder symptoms as we get older because our bodies start to become accustomed to fighting these types of infections,” he said. “But unfortunately, you can catch hand, foot and mouth disease more than once.”

One of the key ways to prevent hand, foot and mouth disease is to practice “good hand hygiene,” said Dr. Yen. That means “not just rinsing your hands with water, but thoroughly handwashing with soap as we have always discussed.”

Proper handwashing is something “we should be teaching our kids anyway with most infectious illnesses,” he said.

Beyond hand hygiene, “disinfecting other surfaces that might come in contact with those body fluids is important,” Dr. Yen said. “This is especially important in younger kids—toddlers and even infants—who are playing with toys and touching a lot of surfaces.”

That is “because they’re exploring their environment, so it’s important to try to disinfect those when possible,” he said. “Just cleaning them thoroughly and even at day care, that is so important for preventing hand, foot and mouth disease.”