Hand, Foot, and Mouth Disease (HFMD) is a common viral infection that frequently affects young children. A child can get HFMD more than once. This article explains why reinfection is possible and provides guidance on managing and preventing future occurrences.
Understanding Hand, Foot, and Mouth Disease
Hand, Foot, and Mouth Disease is a contagious illness caused by viruses, primarily those belonging to the enterovirus family. It commonly affects infants and children under five years old, though older children and adults can also contract it. The illness typically manifests with a fever, sore throat, and a general feeling of unwellness.
Following these initial symptoms, painful, blister-like sores often develop in the mouth, on the tongue, and inside the cheeks. A rash of red spots, sometimes with blisters, usually appears on the palms of the hands and soles of the feet. This rash can also extend to the buttocks, legs, and arms. HFMD is usually a mild condition, with symptoms resolving on their own within 7 to 10 days.
The virus primarily spreads through close personal contact, such as touching an infected person or contaminated surfaces. It can also transmit through respiratory droplets from coughs and sneezes, or contact with fluid from blisters or the stool of an infected individual. The illness is most contagious during the first week of symptoms, but the virus can remain in the stool for several weeks after recovery.
The Science Behind Reinfection
Reinfection with Hand, Foot, and Mouth Disease is possible because the illness is caused by multiple strains of enteroviruses. The most common culprits are Coxsackievirus A16 (CVA16) and Enterovirus 71 (EV71), but other Coxsackievirus strains can also lead to the disease. When a child gets HFMD, their immune system develops specific antibodies that provide immunity only to the particular viral strain that caused that infection.
This means that while a child gains protection against the specific strain they were infected with, they remain susceptible to other strains of the virus. For instance, if a child contracts HFMD from Coxsackievirus A16, they generally develop immunity to A16. However, they could still get HFMD again if later exposed to Enterovirus 71 or another Coxsackievirus strain. Immunity is strain-specific, not providing broad protection across all enterovirus types.
The varying epidemiology of these viral strains contributes to the potential for reinfection. Different strains may circulate in communities at different times, increasing the likelihood of encountering a new one. This genetic diversity among the enteroviruses explains why a child can have repeated bouts of the illness.
Preventing and Managing Future Occurrences
Preventing the spread of Hand, Foot, and Mouth Disease largely relies on consistent hygiene practices. Frequent and thorough handwashing with soap and water for at least 20 seconds is important, especially after changing diapers, using the toilet, and before eating. Parents should teach children to wash their hands regularly and avoid touching their face with unwashed hands.
Disinfecting frequently touched surfaces and shared items, like toys and doorknobs, can help reduce the viral presence in the environment. Avoiding close contact with infected individuals, such as hugging or sharing eating utensils and cups, also minimizes transmission risk. Keeping a child home from school or daycare while they have a fever or open blisters helps prevent further spread within group settings.
If a child does experience HFMD again, managing symptoms focuses on comfort and preventing dehydration. Over-the-counter pain relievers like acetaminophen or ibuprofen can help alleviate fever and mouth pain. Encourage fluid intake, as mouth sores can make swallowing painful. Offering cool liquids, soft foods like yogurt or applesauce, and even ice pops can provide hydration and comfort. Seek medical attention if a child shows signs of dehydration, such as reduced urination, or if symptoms worsen, including a high fever lasting more than three days, extreme fussiness, or signs of severe complications like a stiff neck or difficulty breathing.