Hand, foot, and mouth disease, which will be referred to as HFM for the remainder of this article, is a very common viral illness seen in young children. HFM is commonly seen in outbreaks and epidemics during the summer and early fall months.


The transmission of this virus is via the fecal-oral route and additionally with contact of open skin lesions. The disease is very transmissible and can be seen in outbreaks at schools, day cares, and any other place where close contact is possible.


The responsible pathogen is classically Coxsackie A virus. Students should know this for examinations as well as pimping points in the pediatric, urgent care, and family medicine clinics. Other causative agents worth mentioning include Enterovirus 71, which is commonly seen in the summer as well. One should note that there is an incubation period of 3 to 5 days (Wheelock, 2016). It is possible for patients to pass viral parts in stool weeks after being ill, increasing transmissibility.


When evaluating a patient suspected of HFM, the history may give helpful clues to the diagnosis. Many times, there may be a history of day care exposure or school exposure. Patients may complain of intense pain in the mouth, throat. In those too young to speak, refusal to eat or drink is characteristic. Rash on the hands, feet, mouth is characteristic as well as fever.


On exam, the diagnosis is usually obvious in the correct setting. Patients will have evidence of tender vesicular ulcers on the buccal mucosa, tongue, and posterior pharynx. Early in the course, they may present as papules, but will progress to fluid filled vesicles. Skin involvement may show a macular, maculopapular, or vesicular rash depending on the course and duration of illness. Rash can also be seen on the palms, soles, buttocks, torso. Fever usually is not greater than 101 F.


The differential diagnosis in this condition can be broad, as there are many causes of pediatric enanthems and exanthems. One should consider herpes simplex infection, scarlet fever, erythema multiforme, Kawasaki disease, Fifth’s Disease, Roseola infantum, and any other disease that may cause rash in a pediatric patient.


As discussed previously, the disease is typically diagnosed based on history and physical alone. In the correct setting of a previous outbreak or exposure, the presentation is usually quite obvious. If there is doubt, it is possible to do a culture from the oral lesions, or from an open vesicle. This is not typically performed. PCR swabs are available to identify Enterovirus 71.


The treatment for HFM is typically symptomatic and supportive. Patients should be encouraged to use Tylenol and ibuprofen to help alleviate pain and fever. Spicy foods should be avoided. Numbing sprays available over the counter may be helpful, but can be challenging to administer to infants. The most important concern is restoring fluid balance. Compounding medications of lidocaine should be used cautiously, as there is risk for lidocaine toxicity. Parents can be counseled that the disease will remit in 7 to 10 days.


One of the biggest concerns in young children with HFM is for dehydration. In patients with painful oral ulcers, oral intake can be decreased. In rare cases, dehydration can present a challenge for the parent and clinician. In infants with signs of severe dehydration, hospital visit for hydration via IV may be necessary. Most children can be coaxed into the use of popsicles, ice chips, or back to fluids once the lesions begin to remit.


One should be cautious to make note that there are possible complications to HFM caused specifically by enterovirus 71. This virus has been associated with dehydration, aseptic meningitis, encephalitis. Care should be taken to identify children with potential CNS involvement and should be referred for emergent care as necessary.


Another important question that is common with HFM is when a child can go back to daycare. Many day cares have strict rules regarding fever as well as lesions in the mouth or on the skin. A general rule is once the lesions crust over or when the child does not have fever, but one should recall that even asymptomatic children can pass viral material through stool weeks after an infection, therefore the decision is multi-factorial.


Prevention of HFM spread is very important. Hand washing is of utmost importance. Staff members and parents should be vigilant about hand washing and clean clothing, toys to help prevent spread. Parents should be encouraged to wash hands after changing diapers.





References


Romero, J.R. (2018). Hand, Foot, and Mouth Disease and Herpangina. UpToDate. Date of Access 3 June 2018.


Wheelock, Chris (2016). Hand Foot and Mouth Disease. The 5 Minute Clinical Consult.


This article, blog, or podcast should not be used in any legal capacity whatsoever, including but not limited to establishing standard of care in a legal sense or as a basis of expert witness testimony.No guarantee is given regarding the accuracy of any statements or opinions made on the podcast or blog.