Hand, Foot, and Mouth Disease (HFMD) is a contagious viral illness caused by a group of enteroviruses, most frequently Coxsackievirus A16. Although commonly known as a childhood ailment, this infection can be contracted by people of any age. Adults often acquire the virus from household members, especially infants or young children exposed in daycares or schools. The adult immune system may not have previously encountered the specific viral strain, making them susceptible to infection.
How the Virus Spreads to Adults
Hand, Foot, and Mouth Disease transmits primarily through close personal contact with an infected person. The virus is present in an infected person’s nose and throat secretions, such as saliva or nasal discharge, and in the fluid from the characteristic skin blisters. Contact with these bodily fluids is the main route of transmission.
The virus also sheds in the stool of an infected person, which facilitates the fecal-oral route of transmission, especially in environments involving diaper changing or improper restroom hygiene. Contaminated surfaces and objects, such as shared toys, doorknobs, or countertops, can harbor the virus and serve as indirect transmission vectors. After exposure, the incubation period before symptoms appear typically ranges from three to seven days.
Adults are often exposed in settings where young children congregate, such as child care centers or their own homes. The virus can remain in the stool for several weeks after symptoms clear, allowing a person to continue spreading the infection. Some adults can also carry and transmit the virus without ever developing noticeable symptoms themselves.
Recognizing Adult Symptoms
Adult symptoms of HFMD often begin with non-specific flu-like complaints, including a mild fever, sore throat, and malaise. This initial phase can make the infection difficult to distinguish from other common viral illnesses. Within a day or two, the hallmark signs of the disease usually develop.
The rash and blisters associated with HFMD can be more painful in adults compared to children. Lesions frequently appear on the palms of the hands and the soles of the feet, starting as small, flat red spots that progress into painful blisters. Adult blisters can be extremely tender and may sometimes affect other areas, including the torso, arms, legs, or genital area.
Painful mouth sores, or ulcers, are another distinguishing feature, often appearing on the tongue, gums, and inside the cheeks. These ulcers can be severe enough to cause significant difficulty and pain when swallowing, leading to reduced fluid and food intake. In some cases, adults experience greater systemic illness, including muscle aches and joint pain, intensifying the overall feeling of sickness.
A unique delayed symptom is onychomadesis, which involves the temporary shedding or loss of fingernails and toenails weeks or months after the initial infection. This phenomenon is not dangerous, as the nails will regrow. While most adults recover within seven to ten days, the discomfort from the painful lesions can persist for several weeks.
Treating Hand Foot and Mouth Disease
Since HFMD is caused by a virus, treatment focuses on supportive care to manage symptoms until the illness resolves. Over-the-counter pain relievers, such as acetaminophen or ibuprofen, can reduce fever and alleviate pain from mouth sores and body aches.
Maintaining adequate hydration is particularly important because the painful mouth ulcers can make swallowing liquids difficult. Cold beverages, ice chips, or ice pops are often easier to consume than warm or hot drinks. It is advisable to avoid acidic, spicy, or salty foods, as these can irritate the sores and increase oral pain.
For localized relief of the mouth sores, topical numbing agents or anesthetic mouthwashes are sometimes recommended to temporarily dull the pain before eating or drinking. Gargling with warm salt water can also offer soothing relief for the throat and mouth discomfort. If an adult experiences signs of dehydration, such as reduced urination or excessive fatigue, or if symptoms are severe and persist beyond ten days, consulting a healthcare provider is necessary.
Preventing Transmission and Infection
Preventing the spread of HFMD relies heavily on stringent hygiene practices, especially in households with young children. Frequent and thorough handwashing with soap and water for at least 20 seconds is the most effective measure, particularly after using the restroom, changing diapers, or before preparing food. Adults should also avoid touching their eyes, nose, and mouth with unwashed hands.
Disinfecting high-touch surfaces regularly helps eliminate viral particles that can survive on environmental objects. This includes sanitizing toys, countertops, doorknobs, and shared electronic devices. Using a disinfectant solution that is effective against viruses is recommended for these common areas.
To prevent person-to-person spread, individuals with active HFMD symptoms should avoid close contact, such as hugging or kissing, and should not share eating utensils or drinking cups. Adults who are symptomatic should stay home from work or public settings, especially during the first few days of the illness when the fever and blister fluid are highly contagious. They should remain home until the fever has resolved for 24 hours without the use of fever-reducing medication.