Hand, Foot, and Mouth Disease (HFMD) is a viral infection caused by enteroviruses, commonly Coxsackievirus A16. While often associated with infants and young children, adults can contract the virus, usually through close contact with infected children. The adult experience with HFMD is frequently more severe than the pediatric version, leading to unexpectedly intense symptoms. Since many adults have immunity from childhood exposure, infection later in life occurs from a strain they have not encountered. Outcomes range from being completely asymptomatic to developing a debilitating illness.
How Adult Symptoms Differ
The clinical presentation of HFMD in adults often involves intense initial symptoms. Before the characteristic rash appears, adults frequently report a sudden, high fever, severe headache, and profound malaise similar to a bad case of the flu. Systemic symptoms, such as muscle aches and fatigue, are often more pronounced and linger longer than in children.
When lesions emerge, they may be fewer but disproportionately painful, especially the sores that develop in the mouth. These ulcers appear on the tongue, gums, and inside the cheeks, making eating and drinking difficult. While traditionally on the palms and soles, the skin rash may also appear on the knees, elbows, buttocks, or torso in adults.
The rash can be less distinct than the classic small, red spots seen in children, sometimes manifesting as larger, blister-like sores. A notable, though uncommon, complication is onychomadesis, the temporary shedding of fingernails and toenails. This nail loss occurs several weeks after the initial infection has resolved and is associated with the Coxsackievirus A6 strain.
Treating and Managing Discomfort
Since HFMD is a viral infection, treatment focuses on alleviating symptoms. Over-the-counter pain relievers, such as acetaminophen or ibuprofen, manage fever, body aches, and the pain associated with mouth and skin lesions.
Maintaining hydration is a primary concern, as painful mouth sores limit fluid intake. Cool liquids, like water or diluted sports drinks, should be sipped frequently. Acidic beverages, such as fruit juices, should be avoided as they irritate ulcers. Eating soft, bland foods, such as yogurt or mashed potatoes, minimizes discomfort while ensuring adequate nutrition.
Localized Relief
For localized mouth pain, topical anesthetic sprays or rinses containing lidocaine provide temporary relief before meals. Discomfort from the skin rash may be soothed with cool compresses, oatmeal baths, or calamine lotion. Medical attention should be sought if an adult shows signs of dehydration, such as reduced urination or excessive lethargy, or if a high fever persists beyond three days.
Preventing Transmission
An adult infected with HFMD is most contagious during the first week of illness, particularly when fever and mouth blisters are present. The virus spreads through respiratory droplets, direct contact with blister fluid, and via the fecal-oral route. Transmission is possible before symptoms appear and for a period after they have resolved.
The virus can continue to be shed in the stool for several weeks after symptoms have cleared. Strict hand washing with soap and water for at least 20 seconds should be performed frequently, especially after using the restroom or changing diapers. Alcohol-based hand sanitizers are not always effective against the enteroviruses that cause HFMD.
Contaminated surfaces should be thoroughly disinfected with a chlorine-containing solution, including shared items like doorknobs, remote controls, and countertops. To protect vulnerable individuals, such as infants, pregnant people, and those with compromised immune systems, avoid close personal contact during the acute phase of the illness. Continued vigilance in hygiene prevents the prolonged spread of the virus.