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

• Seborrheic keratosis

• Hypertrophic actinic keratoses

• Squamous cell carcinomas

• Condylomata lata of secondary syphilis

• Molluscum contagiosum

• Varicella zoster (in AIDS)

Diagnosis

• Clinical

• Biopsy may be necessary for definitive diagnosis

Treatment

Medications

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 darkly 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

• Podophyllin

  • Ineffective for common warts and plantar warts

  • Contraindicated in pregnant women

• Imiquimod should not be used to treat plantar or common warts

• 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, nail ...