Description

• Warts are caused by the human papillomaviruses (HPV)
• Mechanism: Localized cellular proliferation and vascular growth lead to development of skin lesions that are typically verrucous and hyperkeratotic
• Lesions resolve spontaneously in most cases:
  • About 30% within 6 mo
  • 60–70% within 2 yr
  • 90% within 5 yr
• Types of cutaneous warts:
  • Verrucae vulgaris (“common warts”):
    • Typically found on: Dorsum of hands, sides of fingers, and adjacent to nails
    • Usually asymptomatic
  • Verrucae plantaris (“plantar warts”):
    • Typically found on: Weight-bearing parts of sole: Heels, metatarsal heads
    • Often symptomatic and painful
    • More common in adolescents and young adults
  • Verrucae plana (“flat, juvenile warts”):
    • Typically found on light-exposed areas: Head, face, neck, legs, dorsum of hands
    • Small in size
    • Range from a few to hundreds
• Anogenital warts:
  • Known as condyloma acuminata or venereal warts
  • Most are asymptomatic and may go unrecognized
  • HPV types 6 and 11 account for 90% of anogenital warts

Etiology

• HPV is host-specific to humans:
  • Cause infection of epithelial tissues and mucous membranes
  • Infects the basal layer of skin or mucosa
• There are >100 types of HPV that variably infect different body sites (i.e., HPV1 tends to infect soles of feet)
• HPV transmission is:
  • Direct: Skin to skin, mucosa to skin, etc.
  • Indirect: Contaminated surface to skin
  • Autoinoculation: Scratching, sucking (especially in young children)
• Incubation period can range from weeks to >1 yr; however, most common range is 2–6 mo

• 10–20% of children will have warts
• Peak incidence between 12–16 yr
• May produce laryngeal papillomatosis in infants from viral exposure at birth
• Must consider sexual abuse in children with anogenital warts