Hand Foot and Mouth (HFM) Disease

What is hand foot and mouth (HFM) disease?

Hand foot and mouth disease (HFM) is a viral infection characterized by fever and a typical rash most frequently seen on the palms of the hands, soles of the feet, and inside the mouth. It should not be confused with foot (hoof) and mouth disease that affects cattle, sheep, and swine.

What are the symptoms and signs of hand foot and mouth disease?

HFM is most commonly an illness of the spring and fall seasons. Initial symptoms of mild fever (101 F-102 F) and malaise are followed within one or two days by a characteristic rash. Small (2 mm-3 mm) red spots that quickly develop into small blisters (vesicles) appear on the palms, soles, and oral cavity. The gums, tongue, and inner cheek are most commonly involved. The foot lesions may also involve the lower calf region and rarely may appear on the buttocks. Oral lesions are commonly associated with a sore throat and diminished appetite.

What causes hand foot and mouth disease?

HFM is caused by several members of the enterovirus family of viruses. The most common cause is Coxsackie virus A-16; less frequently enterovirus 71 is the infectious agent. The clinical manifestations of routine HFM are the same regardless of the responsible virus. However, patients infected with enterovirus 71 are more likely to experience rare complications (for example, viral meningitis or cardiac muscle involvement).

Picture of characteristic rash and blisters of hand foot and mouth disease

How is hand foot and mouth disease spread?

HFM is spread person to person by direct contact with the infecting virus (either Coxsackie virus A-16 or less commonly enterovirus 71). These viruses are most commonly found in the nasal and throat regions but also in the blister fluid or stool of infected individuals. Infected individuals are most contagious during the first week of their illness. HFM cannot be contracted from pets or animals.
The viruses that cause HFM may remain in the person's respiratory or intestinal tract for several weeks to months after all symptoms have resolved. It is possible, therefore, to transmit the infection even though the formally ill individual has completely recovered. Some individuals (most commonly adults) may exhibit no symptoms during their infection but may unwittingly transmit the illness to those (commonly infants and children) who are not immune.

What is the incubation period for hand foot and mouth disease?

HFM is moderately contagious and spreads from person to person. It cannot be spread by animals. Usually the virus is passed via oral secretions (nasal discharge, saliva, etc.) or via stool. There is a short four- to six-day incubation period between exposure and development of initial symptoms (fever and malaise). A person is most contagious during the first week of illness.

When does hand foot and mouth disease occur?

Spring and fall are the most frequent seasons for community epidemics of HFM. While anyone exposed to the viral causes of HFM may develop disease, not everyone infected will develop symptoms.

How does hand foot and mouth disease affect pregnancy and the baby?

Commonly HFM is an illness of children less than 10 years of age; adults generally were exposed during childhood and maintain a natural immunity. Information regarding fetal exposure to HFM during pregnancy is limited. No solid evidence exists that maternal enterovirus infection is associated with complications such as spontaneous abortion or congenital defects. However, should a baby be born to a mother with active HFM symptoms, the risk of neonatal infection is high. Typically, such newborns have a mild illness. Rarely, overwhelming infection involving vital organs such as liver, heart, and brain can be lethal.

What is the course of hand foot and mouth disease?

The illness is characteristically self-limited and is usually resolved within a week, particularly when due to its most common cause, Coxsackie virus A-16. In those outbreaks due to enterovirus 71, the illness may be more severe with complications such as viral meningitis and encephalitis and paralytic disease. As a rule, HFM is generally a mild and self-limited illness.

Why haven't we heard more about hand foot and mouth disease?

Recognition of hand foot and mouth disease is relatively recent (as compared to mumps, measles, and chickenpox, for example). HFM was first reported in 1956 in Australia. By the early 1960s, it had emerged as a common childhood illness around the world.

How is hand foot and mouth disease diagnosed?

Usually, the diagnosis of HFM is made on a combination of clinical history and characteristic physical findings. Laboratory confirmation is rarely necessary unless severe complications develop.

What is the treatment for hand foot and mouth disease?

Therapy for HFM is directed toward symptomatic relief of fever and sore throat. Antibiotics are not indicated for this viral disease.

Hand Food and Mouth (HFM) Syndrome At A Glance

• Hand foot and mouth disease is a viral disease.
• Hand foot and mouth disease produces a rash on the hands, feet, and in the mouth.
• Hand foot and mouth disease often occurs in the spring and fall.
• Hand foot and mouth disease is common in kids, particularly preschoolers.
• Hand foot and mouth disease usually is mild and over within a week. Treatment is directly toward relief of symptoms (fever and sore throat).

REFERENCE:

American Academy of Pediatrics. Red Book: 2009 Report of the Committee on Infectious Diseases. 28th ed. Elk Grove Village, IL: American Academy of Pediatrics, 2009.

Medical Author:

John Mersch, MD, FAAP

Medical Editor:

William C. Shiel Jr., MD, FACP, FACR
Source:Medicinenet.com.