Characteristics of Rash in Hand, Foot, and Mouth Disease
The rash in hand, foot, and mouth disease (HFMD) typically presents as small, erythematous maculopapular lesions that evolve into tender vesicles or papules primarily on the hands, feet, and oral mucosa, with possible extension to the buttocks and other body areas. 1
Cutaneous Manifestations
Classic Presentation
- Distribution: Primarily affects palms of hands, soles of feet, oral cavity, and sometimes buttocks 2
- Morphology:
- Initial appearance: Erythematous maculopapular lesions
- Evolution: Progresses to tender vesicles or papules
- Size: Small, discrete lesions
- Timing: Typically appears within the first five days of illness, often after fever onset 3
Oral Lesions (Enanthem)
- Painful ulcerations in the mouth, palate, and pharynx 2
- May present as red and cracked lips or strawberry tongue
- Often the first clinical signs of the disease 4
- Can cause significant discomfort and difficulty eating or drinking
Atypical Presentations
Several variants have been reported, particularly with Coxsackievirus A6 infections:
- Vesiculobullous and erosive eruptions
- Extensive cutaneous involvement beyond classic sites
- Periorificial lesions (particularly peri-oral rash, strongly associated with CV-A6) 1
- "Eczema coxsackium" - exacerbation in areas of pre-existing atopic dermatitis 5
- Gianotti-Crosti-like lesions
- Petechial or purpuric eruptions 2
Clinical Course and Evolution
Progression
- Rash typically evolves over 3-7 days
- Lesions generally resolve without scarring
- Total duration of illness usually 7-10 days
Late Manifestations
- Delayed onychomadesis (nail shedding) may occur weeks after initial infection 3, 2
- Palmoplantar desquamation during recovery phase 2
Distinguishing Features from Other Exanthems
- Non-bullous: Unlike other vesicular diseases, HFMD typically doesn't form large bullae
- Distribution pattern: Characteristic acral distribution (hands, feet) distinguishes from many viral exanthems
- Oral involvement: Concurrent oral lesions help differentiate from other conditions
- Absence of specific features: No necrotic lesions (unlike HSV), no target lesions (unlike erythema multiforme)
Variations by Causative Agent
- Coxsackievirus A16: Traditional cause of classic HFMD presentation
- Enterovirus 71: Associated with more severe disease and neurological complications
- Coxsackievirus A6: Linked to atypical and more widespread exanthema, including peri-oral involvement 1
Clinical Pearls
- The presence of fever plus vesicular lesions on hands, feet, and in the mouth is highly suggestive of HFMD
- Widespread exanthema beyond classic sites occurs in up to 87.6% of cases 1
- Adult cases are increasingly recognized, particularly with CV-A6 infections 2
- Diagnosis is primarily clinical, based on characteristic distribution and appearance of the rash
Understanding these characteristic features of HFMD rash helps clinicians make accurate diagnoses and provide appropriate management for this common viral exanthem.