Charles Langston:No one wants hand, foot, and mouth disease. Here's how long you're contagious if you get it.

Hand,Charles Langston foot, and mouth disease is a viral illness known for its rash, mouth sores, and slightly raised red spots or white blisters on the palms of one's hands and the soles of one's feet. These bumps also sometimes spread to other areas of the body such as the belly, legs, or buttocks. 

Though its telltale rash is more common in children than adults, many people who experience hand, foot, and mouth disease also experience a "fever, abdominal pain, and diarrhea," says Dr. Vikash Oza, director of pediatric dermatology at NYU Langone Health. 

Because it's such a common, uncomfortable, and inconvenient disease, it can be helpful to know how the virus spreads - and how long someone who has it is contagious.

How is hand, foot, and mouth disease spread? 

The first thing to understand is that hand, foot, and mouth disease is an illness that's highly contagious and easily spread, per the Centers for Disease Control and Prevention (CDC). 

The public health agency notes that the virus typically spreads by someone coming into direct contact with feces, by touching objects or surfaces that have the virus on them and then touching one's eyes, nose or mouth, and by close personal contact with another person that has the disease. Such interactions could be hugging, kissing, talking or getting sneezed at or coughed on, explains Dr. Kellie Kruger, a board-certified physician in internal medicine and pediatrics at Mayo Clinic in Arizona. 

The virus commonly spreads in the home and in daycare or school settings when practices like washing hands or avoiding putting one's fingers in one's mouth are easily forgotten, and where many kids come into contact with other potentially infected kids. "This is why we often hear about outbreaks in school settings," says Oza. 

How long is hand, foot, and mouth disease contagious?

Regardless of where one has picked up the disease, it's important to know how long one needs to be careful around others. The CDC notes that people are most contagious during the first week they are sick, however, it is possible to spread the virus for longer periods of time. "The infected individual is likely also contagious until all skin blisters have healed," says Oza, but notes that even then, the person can continue "shedding the virus from the stool for up to 6 weeks."

It's also important to note that a person can become infected even before symptoms begin manifesting. "Incubation period is generally 3-5 days, meaning that someone is generally exposed to the virus 3-5 days before developing symptoms," explains Kruger. 

When are you no longer contagious with hand, foot, and mouth disease?

One is usually considered out of the woods once a week or so has passed since symptoms first appeared and after the worst of the blisters or rash have gone away. This means looking out for "crusting and healing of all prior blisters and open sores in the skin," says Oza.

More:Hand, foot, and mouth disease can be painful and inconvenient. Here's what it is.

Kruger says it's especially important to make sure one is fever-free and able to eat "without significant pain." Even then, she adds, "it’s important to continue with strict hand washing after you’re feeling better, because the virus can still be present after the clinical symptoms resolve."