What is the typical presentation and rash pattern of hand, foot, and mouth disease?

Presentation and Rash Pattern of Hand, Foot, and Mouth Disease

Hand, foot, and mouth disease (HFMD) typically presents with fever followed by a characteristic rash on the palms, soles, and in the mouth, with lesions appearing as erythematous maculopapular eruptions that may evolve into vesicles.

Clinical Presentation

Prodromal Symptoms

• Fever (typically 39°C/102°F or higher) 1
• Sore throat 2
• Mild malaise
• Low-grade fever may precede rash by 1-2 days 3

Characteristic Rash Pattern

• Location and Distribution:

  • Palms of hands
  • Soles of feet
  • Oral mucosa (often the first clinical sign) 4
  • May extend to involve buttocks and genitalia in some cases 5

• Appearance of Lesions:

  • Oral lesions: Vesicular and ulcerative lesions in the mouth 4
  • Skin lesions: Erythematous maculopapular eruptions that may evolve into vesicles 3
  • Deep-seated vesicles and papules on palms and soles 3

Timing and Evolution

• Oral lesions are usually the first clinical signs of the disease 4
• Rash typically appears within 1-2 days after fever onset
• Lesions generally regress within 7-10 days 5
• Total disease duration is typically 7-10 days for classic HFMD 5

Special Considerations

Atypical Presentations

• Coxsackievirus A6 (CVA6) strain has been associated with:
  • More severe disease
  • Wider distribution of rash beyond typical areas
  • Higher fever
  • Longer disease duration
  • Affects broader demographics including adults 5

Complications

• Nail dystrophies (e.g., Beau's lines or nail shedding) may occur weeks after initial symptom onset 1
• Onychomadesis (nail shedding) has been reported as a late complication 3

Age-Related Differences

• Most common in children under 5 years 1
• Can occur in adults but less frequently 2
• Adult cases may present with similar symptoms but sometimes with atypical or milder presentations 2

Differential Diagnosis

• Viral infections (measles, adenovirus, enterovirus, Epstein-Barr virus) 6
• Herpangina
• Herpes simplex
• Recurrent aphthae
• Erythema multiforme 4

Epidemiological Patterns

• Most common in summer and autumn months in the United States 1
• Caused primarily by enteroviruses:
  • Traditionally coxsackievirus A16 has been most common in the US 1
  • Enterovirus 71 is another common cause
  • Recent outbreaks increasingly caused by coxsackievirus A6 5

Clinical Pearls

• The diagnosis is primarily clinical, based on the characteristic distribution and appearance of the rash
• Most infections are self-limiting and asymptomatic 1
• Recurrence is rare but possible 3
• Treatment is primarily supportive and aimed at symptom relief 4

Understanding the typical presentation of HFMD is important for prompt diagnosis and appropriate management, especially in outbreak settings where early recognition can help prevent transmission.