Viral Papules and Plaques

Question 1

Human Papilloma Virus (HPV)

Answer 1

Viral Papules and Plaques
Papillomaviridae
• Double-stranded, circular DNA genome 
• Replicates in the nucleus
• Icosahedral
o Naked (non-enveloped) 
• Small (52-55 nm)
• Requires host polymerase
• Strictly epitheliotropic w/ **tropism for mucosal or cutaneous epithelium 
• transmission direct skin-skin contact
DISEASE
Cutaneous warts = Verrucae (singular Verruca)
Types of Cutaneous Warts
1. Common wart = Verruca Vulgaris
• *firm hyperkeratotic papules, ~1-10 mm,
• *rough irregular surface
• *red or brown dots 
• anywhere, but often *hands, knees
2. Plantar wart= Verruca Plantaris
• small, shiny, sharply marginated papule→ plaque w/ rough - hyperkeratotic surface
• brown to black dots 
• on *sole of foot, palms
3. Flat wart= Verruca Plana
• sharply defined flat flesh-colored papules, 1-5 mm diam. (1-2 mm thick)
• Anywhere, but often *face, hand, shin

Question 2

Molluscum Contagiosum Virus (MCV)

Answer 2

Viral Papules and Plaques
Poxviridae
• *Double-stranded, linear DNA genome 
• Replicates in the *cytoplasm (NOT NORMAL)
• Helical/complex
• Enveloped (lipoprotein) 
• *brick-shaped or ovoid
• Large (220-450 nm long)
• *Stable in environment
• Human reservoir
• more common *kids
• Direct contact, fomites, STI
• *Contagious, including endogenous
• Infects *epidermal keratinocytes
• Includes Variola virus (smallpox)
DISEASE
- causes *molluscum contagiosum
   • *Benign, cutaneous
   - Anywhere *except palms
   • Small, *wartlike, pale, firm, painless nodules in epidermis
   - *Central caseous plug that can be squeezed out
   • *No systemic symptoms
   • *Self-limiting 2-12 mo.
   - *some association w/ *HIV
DIAGNOSIS
- *molluscum bodies found histologically

Question 3

Pityriasis Rosea

Answer 3

Viral Papules and Plaques
o viral-like structures w/ electron micros
o sometimes preceded by a *prodrome
• headache, malaise, pharyngitis
o occasionally occurs in *small case clusters
o *no bacteria or fungi associated
DISEASE
- causes Pityriasis Rosea
• Older children, young adults
• Acute, self-limited, exanthematous skin disease
• characterized by appearance slightly inflammatory, oval, papulosquamous lesions
• on trunk and proximal areas of extremities
• Eruption often heralded by **herald patch
- becomes scaly, clears centrally= *collarette scale
o long axis of oval plaques is oriented along skin lines = *Christmas-tree distribution
• *Mild pruritis, mild, typically the only sx
• Usually resolves in 4-6 wks