Chapter 38. Common Warts: Cryotherapy

• • Parent’s or child’s desire for office-based treatment.

Relative

• • Child unable to undergo painful procedure.

  • Some physicians consider verruca in a periungual location a contraindication to destructive therapies (nail matrix damage may occur and result in permanent nail dystrophy).

  • History of keloidal scarring.

• • Dipstick method.

  • • Liquid nitrogen (–195.8 °C).

    • Cotton-tipped applicators.

    • Cotton balls.

    • Styrofoam cup.

    • Extra cotton can be rolled onto cotton-tipped applicators.

  • Spray devices

  • • Cryospray canister filled with liquid nitrogen.

    • Children may be afraid of these spray canisters and often have less anxiety with the dipstick method.

• • Treatment causes blistering and rarely scarring.

  • Temporary hyperpigmentation or hypopigmentation.

  • Hypertrophic or keloidal scarring is rare.

• • Pretreatment of the area with paring or salicylic acid may decrease the wart hyperkeratosis and increase the treatment success rate.

  • Pretreat for pain with acetaminophen or ibuprofen 1 hour before the procedure.

  • The goal of treatment is tissue destruction through skin blistering.

• • For the first week, there will be a blister that may be hemorrhagic that turns into a scab or crust, which comes off in approximately 2 weeks. The area can be cleaned with soap and water and covered with a topical antibiotic ointment and a bandage.

  • There are no limitations on physical activity unless pain results from the activities.

  • Acetaminophen may be required for the first 1–2 days after treatment for discomfort.

  • Several treatments are often needed.

• • Patient should be positioned so that physician has close access to lesions.

  • Good lighting is helpful.

• • Cotton-tipped applicators should be placed in a cup of liquid nitrogen until thoroughly soaked.

  • Apply to wart until white frost develops approximately 2 mm around the wart (Figure 38–1).

• • • A freeze-thaw cycle (time when wart becomes frozen white until return of pink skin) of 20–30 seconds is suggested.

    • Wart should be kept frosted for 10–15 seconds to obtain a 20 second freeze-thaw.

  • Freeze-thaw times from spray devices are the same as for the cotton applicators.

  • An adequate freeze-thaw time is easy to estimate with time and experience.

• • Pain is expected and can be treated with acetaminophen or ibuprofen.

  • Although rare, secondary bacterial infection of the blistered area can occur.

• • Most young children will not tolerate the discomfort of this therapy.

  • Over-the-counter topical salicylic acid products with or without tape occlusion can be used if cryotherapy is not tolerated.

• • Treatment can be repeated approximately every 3 weeks when the old blister peels off.