Hand-Foot-and-Mouth Disease

Hand-foot-and-mouth disease (HFMD) is the most familiar enteroviral exanthem and typically occurs in 1- to 4-year-old children as a vesiculopustular eruption with a characteristic distribution.

HFMD is most often caused by coxsackievirus A16 but can also result from other enteroviruses including other coxsackie A and B serotypes, echoviruses, and enteroviruses.
The virus is spread via the fecal-oral route and the incubation period ranges from 4 to 6 days.
Outbreaks typically occur in the summer or early fall.

A 1- to 2-day prodrome of fever, malaise, and abdominal pain may be seen.
The illness most frequently begins as a sore throat or mouth and refusal to eat secondary to the oral lesions (enanthem) of HFMD (Fig. 7.7).
The enanthem presents as 1- to 5-mm vesicles or shallow erosions often with a rim of erythema.
The exanthem follows the development of oral lesions and presents as round or angulated, grayish white tense vesicles that are typically 3 to 7 mm in diameter (Fig. 7.8).
Lesions are usually not pruritic although they may be painful.
In contrast to most viral illnesses, lymphadenopathy is absent to minimal.
Although in general complications are rare, the one seen most frequently is aseptic meningitis.

Diagnosis is made on the basis of the characteristic clinical presentation and distribution of lesions.
Although not routinely indicated, laboratory testing can confirm the diagnosis. The virus can be cultured or detected with PCR from throat washings or stool, with the latter giving a higher yield.
Acute and convalescent sera show an elevation in antibody titer to the causative virus.

Management

Treatment is with supportive care.
Treat fever and pain with acetaminophen and ibuprofen.
It is most important to encourage continued intake of liquids to prevent dehydration.
Ice pops and cold liquids can help throat pain.

Point to Remember

Differential Diagnosis

Primary Oral Herpes Simplex (see Chapters 6 and 17)

Aphthous Ulcers

Lesions are painful.
As with herpes simplex, the lips and gingiva are usually affected, and the back of the throat is spared.

Herpangina

Small, painful vesicular or ulcerative lesions occur on the roof of the mouth and in the throat.
White to whitish-gray base and a red border.
Usually caused by coxsackie virus, typically coxsackie group A viruses.
Typically occurs during the summer and frequently affects children, but it also may occur in young adults.
Mouth ulcers, high fever, sore throat, and headache are the characteristics.
Systemic symptoms may precede the appearance of lesions.

Distribution of Lesions

The enanthem appears most commonly on the tongue and buccal mucosa and occasionally on the lips, palate, and gums.
The exanthem is characteristically present on the palms and soles and less often on the dorsal or lateral aspects of the fingers and toes. All three sites may not be involved at the time of presentation. A typical cutaneous lesion has an elliptical vesicle surrounded by an erythematous halo. The long axis of the lesion is oriented along the skin lines (Fig. 7.9).
Occasionally the eruption is more widespread on arms and legs.
The diaper area in infants is also a common area of involvement.
Occasionally, lesions may extend onto the proximal extremities.