plantar wart

Etiology

• all warts are caused by human papilloma virus (HPV)
• HPV types 1,4
• immunosuppression increases risk of severe cases

Clinical manifestations

• occur on the plantar aspect of the foot
• most frequently occurs at pressure points
  • heel
  • metatarsal head
• endophytic papule or verrucous plaques, partially or fully inverted
  • dry rough surface that interupts the normal skin lines
  • pinpoint hemorrhagic macules of thrombosed capillaries
  • 2 cm plantar wart on heel not unusual
• may be exophytic in non-mobile patients
• covered by a thick callus
• skin-colored with black punctae (capillary loops) on close inspection or after removal of callus
• tender with pressure

* image of severe case in immumocompromised woman

Differential diagnosis

• plantar corns
• Tinea pedis (erythematous, often involves interdigital webspaces with maceration)
• erythrasma
  • macules, generally large & scaling, sharply marginated
  • pink/red to brownish red in color
  • intertriginous areas of toes, groin & axillae
  • skin folds: groin, subpanniculus, intergluteal, inframammary
  • skin often has thin, wrinkled appearance similar to cigarette paper
  • Wood's lamp: coral-red fluorescence
• pitted keratolysis
  • manifests as scale & pitting of the skin surface
  • involved areas are white when stratum corneum is fully hydrated
  • toe webs, balls or heel of foot in contact with shoe
  • foot odor (malodorous)
  • hyperhidrosis
• black heel
  • can mimic the thrombosed capillaries of plantar warts
  • black heel lesions do not obscure dermatoglyphics & can be removed by scraping
    • this differentiates them from plantar warts

Management

• see verruca vulgaris (wart)
• pharmacologic agents
  • podophyllin 25% resin solution applied weekly
  • cantharidin, 0.7% colloidin solution
• cryotherapy every 2 weeks as effective as topical salicylic acid & a visa versa
  • 6 month cure rate 31-34%

More general terms

• verruca vulgaris (warts)

Additional terms

• papillomavirus