What are the typical presentations, possible complications, diagnostic approach, and recommended supportive management for Coxsackievirus infection in adults?

Coxsackievirus Infection in Adults

Clinical Presentation

Coxsackievirus infections in adults most commonly present as hand, foot, and mouth disease (HFMD), which was historically rare in immunocompetent adults but has become increasingly recognized, particularly with Coxsackievirus A6 strains causing more severe and widespread disease since 2008. 1, 2

Typical Features

• Vesicular eruptions on hands, feet, and oral cavity are the hallmark presentation 1, 2
• Painful papules and vesicles on palms and soles, often with oral vesicles 3
• Fever commonly accompanies the rash 4
• Myalgia and arthralgia may be prominent, particularly with CVA6 infections 4
• The disease is highly contagious and can be transmitted from children to immunocompetent adults through familial contact 1, 3

Atypical Presentations (Particularly CVA6)

• Widespread vesiculobullous eruptions extending beyond classic hand-foot-mouth distribution to trunk and extremities 1, 2
• Perioral zone involvement 1
• Purpuric and targetoid lesions on hands and feet 4
• Crusted, pruritic papules on scalp, ears, and face 4
• Delayed complications including onychomadesis (nail shedding) and desquamation of palms and soles occurring weeks after initial infection 2

Serious Complications

While most adult cases follow a benign, self-limiting course 1, serious complications can occur:

Neurological Complications

• Meningitis is a recognized complication of enterovirus infections, including Coxsackievirus 5
• Encephalitis has been reported, though more commonly in children 1
• Neurologic symptoms including headache and altered mental status may occur with severe CVA6 infections 4

Other Severe Complications

• Myocarditis 1
• Pulmonary edema 1
• These complications have been reported mostly in children but can occur in adults 1

Diagnostic Approach

Clinical Diagnosis

Diagnosis is primarily clinical based on the characteristic distribution of vesicular lesions on hands, feet, and oral cavity in the appropriate epidemiological context (e.g., exposure to infected children). 1, 2, 3

Laboratory Confirmation

• Real-time reverse transcription-polymerase chain reaction (qRT-PCR) is the gold standard for confirming Coxsackievirus infection 2, 3
• Samples should include vesicle fluid, throat swabs, and rectal swabs 3
• Standard serologic testing by complement fixation typically does not detect CVA6, which is now the predominant strain 2
• Serologic assays may show cross-reactivity and false positives 2

When to Suspect Meningitis/Encephalitis

If patients develop:

• Altered consciousness (suggests encephalitis rather than simple viral meningitis) 5
• Severe headache with neck stiffness and photophobia (meningism) 5
• Personality or behavioral changes 5

Perform lumbar puncture with CSF PCR testing for enteroviruses (which includes Coxsackievirus), HSV-1, HSV-2, and VZV 5

Management

Supportive Care

There is no specific antiviral treatment for Coxsackievirus infections; management is entirely supportive with analgesia and hydration. 5

• Analgesia for painful oral and cutaneous lesions 5
• Adequate hydration and fluids if oral intake is compromised 5
• Rest during the acute illness 6
• Avoidance of irritants that may worsen symptoms 6

Hospitalization Criteria

Some patients with severe CVA6 infections may require hospitalization for supportive care, particularly those with:

• Widespread painful eruptions 4
• High fevers 4
• Severe arthritis 4
• Neurologic symptoms 4

Infection Control

Immediate isolation and infection control measures are critical given the highly contagious nature of the disease 3

When NOT to Use Antivirals

• Aciclovir/valaciclovir should NOT be given for enteroviral meningitis, as there is no evidence of benefit for non-herpes viral causes 5
• If encephalitis is suspected (altered consciousness, personality changes), intravenous aciclovir should be given empirically for possible HSV encephalitis until HSV is excluded 5

Clinical Pitfalls to Avoid

• Do not dismiss HFMD in adults as "just a childhood disease" – CVA6 has changed the epidemiology, causing severe disease in immunocompetent adults 1, 2, 4
• Do not rely on standard serologic testing for diagnosis, as it misses CVA6 and shows cross-reactivity 2
• Do not overlook atypical presentations with widespread distribution beyond hands, feet, and mouth 1, 2
• Watch for delayed complications like onychomadesis occurring weeks after apparent recovery 2
• Maintain high suspicion for neurological complications if headache, altered consciousness, or meningism develop 5, 1
• Recognize that complete recovery is expected in immunocompetent adults with uncomplicated disease 1