IN THIS ARTICLE
- Outcome for the case patient
An 18-year-old woman presents to urgent care with a one-day history of sudden-onset sore throat, chills, malaise, and fever (102.5°F). On physical examination, the tonsils and pharynx are erythematous, and anterior cervical lymph nodes are tender on palpation. A rapid strep test is negative. The patient is instructed to use throat lozenges and take ibuprofen (400 mg every 8 h) as needed for pain.
On day 2, the patient’s fever resolves, but a painful rash develops on her palms and soles. Clinical examination reveals multiple erythematous plaques on the hands and feet (see Figure 1). The patient is diagnosed with hand-foot-and-mouth disease (HFMD).
HFMD is caused by enteroviruses, most commonly coxsackievirus A16 (CV-A16) or enterovirus 71 (EV71).1 However, a newly recognized strain, CV-A6, has caused worldwide outbreaks of HFMD in both children and adults. Although less common than CV-A16 or EV71, CV-A6 is associated with a more severe disease course.1 The CV-A6 strain was first identified in Finland in 2008 during a major outbreak of HFMD; it reached the United States in 2011.2,3 Accurate statistics on the prevalence of CV-A6 in the US are difficult to obtain because HFMD is not a reportable condition.
HFMD typically manifests with painful oral lesions, with or without a macular, maculopapular, or vesicular exanthema. If a fever is present, it is usually below 101°F. The oral lesions are typically benign and manifest as erythematous macules that progress to vesicles with an erythematous halo. These lesions tend to be painful and may interfere with eating or drinking. Signs and symptoms associated with the more virulent form, CV-A6, may include
- Higher fever
- Wider distribution of lesions
- More extensive skin involvement
- Longer duration
- Palmar and plantar desquamation
- Nail dystrophy.4,5
Most symptomatic enterovirus infections are diagnosed based on clinical findings alone, reducing the need for laboratory testing. Laboratory confirmation may be warranted for more severe infections and during outbreaks. Molecular methods, such as reverse transcriptase polymerase chain reaction, are typically used for identifying enteroviruses, as they are rapid, sensitive, and widely available in hospital and commercial laboratories.6 Viral culture methods are labor-intensive, expensive, and reserved for typing the isolate. Serology is not useful in the diagnosis of acute infection.
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