Viral Warts (Verrucae)

Introduction

Viral Warts is an infections caused by human papilloma viruses (HPV); include more than 80 types.

  • Transferred between humans, or from animals to humans
  • Cause cutaneous tumours which tend to regress spontaneously but may rarely progress into cutaneous malignancies

Symptoms and Clinical features of viral warts

Infection may be clinical, subclinical, or latent

  • Clinical lesions are visible by gross inspection
  • Subclinical lesions may be seen only by aided examination (e.g. the use of acetic acid soaking)
  • Latent infection:
    • HPV virus or viral genome is present in apparently normal skin
    • Thought to be common, especially in genital warts, and explains in part the failure of destructive methods to
      eradicate warts
  • Incubation period is highly variable; from weeks to years
  • Auto-inoculation is the rule
  • Lesions may also occur on scratches
    (Koebner phenomenon)

Lesions are classified according to their positions and shape:

Common warts

  • Firm growths with rough surface; round or irregular, greyish or brown
  • Generally appear on areas that are frequently injured, such as the fingers, around the nails (periungual warts); knees, face and scalp

Plantar warts

  • Develop on the soles of the feet, where they are usually flattened by the pressure of walking
  • A reactive callus forms around lesions
  • Multiple warts may coalesce, resembling a tile or mosaic floor (mosaic warts)
  • May be extremely tender
  • Unlike corns and calluses, plantar warts tend to bleed from many tiny spots, like pinpoints when pared down with a blade

Filiform warts

  • Long, thin, small growths that usually crop up on the eyelids, face, neck, or lips
  • People who chronically use corticosteroids as cosmetic bleaching creams are prone to multiple filiform warts

Plane warts

  • More common in children and young adult.
  • Usually appear in groups as smooth, yellow brown, small, flat papules; most frequently on the face

Genital warts

  • Occur most often on warm, moist surfaces of the body In men, usual sites are the end and shaft of the penis, and below the foreskin (if uncircumcised)
  • In women, lesions occur on the vulva, vaginal wall, cervix, and skin surrounding the vaginal area May develop in the perianal region or rectum
  • Especially in homosexual men, and in women who engage in anal sex
  • Usually appear 1-6 months after infection as soft erythematous papules, which may be greyish if hyperkeratotic
  • New lesions develop rapidly and all coalesce, producing a cauliflower-like picture May grow rapidly in pregnant women, and immunocompromised patients

Differential diagnoses

Common warts

  • Keratoacanthoma
  • Squamous cell carcinoma
  • Seborrhoeic keratosis
  • Hypertrophic lichen planus
  • Tuberculosis
  • verrucosa cutis
  • Palmoplantar keratoderma
  • Arsenical keratoses

Plane warts

  • Epidermodysplasia verruciformis
  • Syringomas
  • Dermatosis papulosa nigra
  • Lichen planus
  • Lichen nitidus

Genital warts

  • Condyloma lata
  • Pemphigus vegetans

Complications of viral warts

  • Squamous cell carcinoma of the perianal skin
  • Cervical carcinoma from anogenital warts
  • Obstructive laryngeal papillomatosis in babies infected through maternal birth canal

Investigations

  • Histopathology if in doubt

Management

  • Treatment depends on their location, type, and severity, as well as duration of lesions

Treatment objectives

  • Eradicate the skin lesions
  • Prevent complications

Non-drug treatment

  • Liquid nitrogen freeze
  • Electro-desiccation
  • Laser surgery

Drug treatment

Salicylic acid with lactic acid plaster

  • Apply carefully to wart; rub wart surface gently with file or pumice stone once weekly
  • May need to treat for as long as 3 months

Podophyllum resin

  • Apply weekly under supervision e.g. in genitourinary clinic

Imiquimod 5% cream

  • Apply thinly once daily on 3 alternate days per week until lesions resolve (maximum 16 weeks)

Notable adverse drug reactions, caution and contraindications

Salicylic acid plaster

  • Avoid broken skin
  • Not suitable for anogenital region or large areas

Podophyllum

  • Avoid normal skin and open wounds
  • Keep away from face
  • Should not stay on treated skin for more than 6 hours before washing

Prevention

  • Women with genital HPV infection should have routine cervical cytologic screening
  • Pappanicolaou (PAP) smear to detect cervical dysplasia