Skip to Main Content

We have a new app!

Take the Access library with you wherever you go—easy access to books, videos, images, podcasts, personalized features, and more.

Download the Access App here: iOS and Android. Learn more here!

For further information, see CMDT Part 6-36: Warts

Key Features

Essentials of Diagnosis

  • Verrucous papules anywhere on the skin or mucous membranes, usually < 1 cm in diameter

  • Prolonged incubation period (average 2–18 months)

  • Spontaneous "cures" (50% at 2 years for common warts)

  • "Recurrences" (new lesions) are frequent

General Considerations

  • Caused by human papillomaviruses (HPVs)

  • Typing of HPV lesions is not a part of standard medical evaluation except in the case of genital dysplasia

  • Genital HPVs are divided into low-risk and high-risk types depending on the likelihood of their association with cervical and anal cancer

Clinical Findings

Symptoms and Signs

  • There are usually no symptoms

  • Tenderness on pressure occurs with plantar warts; itching occurs with anogenital warts

  • Flat warts are most evident under oblique illumination

  • Periungual warts may be dry, fissured, and hyperkeratotic and may resemble hangnails or other nonspecific changes

  • Plantar warts resemble plantar corns or calluses

Differential Diagnosis

  • Nongenital warts

    • Actinic keratosis

    • Squamous cell carcinoma

    • Molluscum contagiosum

    • Skin tag (acrochordon)

    • Nevus

    • Verrucous zoster (in AIDS)

  • Genital warts (condyloma acuminata)

    • Secondary syphilis (condyloma lata)

    • Psoriasis

    • Seborrheic keratosis

    • Molluscum contagiosum

    • Bowenoid papulosis and squamous cell carcinoma

    • Lichen planus

    • Pearly penile papules

    • Skin tag (acrochordon)


  • Clinical

  • Biopsy may be necessary for definitive diagnosis



For Nongenital Warts

  • Liquid nitrogen

    • Apply to achieve a thaw time of 30–45 seconds

    • Two freeze-thaw cycles are given every 2–4 weeks for several visits

    • Scarring will occur if it is used incorrectly

    • May cause permanent depigmentation in pigmented individuals

  • Keratolytic agents and occlusion

    • Salicylic acid products may be used against common warts or plantar warts

      • They are applied, then occluded

    • Plantar warts may be treated by applying a 40% salicylic acid plaster after paring

      • The plaster may be left on for 5–6 days, then removed, the lesion pared down, and another plaster applied

    • Although it may take weeks or months to eradicate the wart, the method is safe and effective with almost no side effects

    • Chronic occlusion alone with water-impermeable tape (duct tape, adhesive tape) is less effective than cryotherapy

  • Immunotherapy

    • Squaric acid dibutylester may be applied in a concentration of 0.2–2% directly to the warts from once weekly to five times weekly to induce a mild contact dermatitis

    • Between 60% and 80% of warts clear over 10–20 weeks

    • Injection of Candida antigen starting at 1:50 dilution and repeated every 3–4 weeks may be similarly effective in stimulating immunologic regression of common and plantar warts

  • Bleomycin

    • Dosage: diluted to 1 unit/mL, injected into common and plantar warts

    • Should be used with caution on digital warts because of the potential complications of Raynaud phenomenon, ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.