From the Guidelines
The procedure for treating warts with a liquid nitrogen gun involves applying the liquid nitrogen in a freeze-thaw cycle pattern, typically freezing the wart for 10-30 seconds until a 1-2 mm white ice field forms around the wart, then allowing it to thaw completely, and repeating this cycle 2-3 times in the same session for optimal results. This treatment works by causing cellular destruction through ice crystal formation and vascular damage to the wart tissue, as described in the guidelines for treating sexually transmitted diseases, including the use of cryotherapy with liquid nitrogen 1. The guidelines emphasize the importance of proper training for healthcare providers in the use of this therapy to avoid complications or low efficacy. Some key considerations for the procedure include:
- Cleaning the wart area with alcohol and allowing it to dry completely before treatment
- Positioning the liquid nitrogen gun approximately 1-2 cm from the wart surface
- Applying the liquid nitrogen in a freeze-thaw cycle pattern
- Freezing the wart for 10-30 seconds until a 1-2 mm white ice field forms around the wart
- Allowing the wart to thaw completely between freeze-thaw cycles
- Repeating the freeze-thaw cycle 2-3 times in the same session for optimal results
- Spacing multiple treatment sessions 2-3 weeks apart for complete wart resolution
- Avoiding treatment of areas with poor circulation and using shorter freeze times on thin-skinned areas like the face or genitals As noted in the guidelines, pain after application of the liquid nitrogen, followed by necrosis and sometimes blistering, is common, and local anesthesia may facilitate therapy if warts are present in many areas or if the area of warts is large 1.
From the Research
Procedure for Treating Warts with Liquid Nitrogen Gun
- The procedure for treating warts with a liquid nitrogen gun, also known as cryotherapy, involves applying liquid nitrogen to the wart until a halo of ice forms around it 2.
- A sustained 10-s freeze is more effective than the traditional method, but it carries a significantly greater morbidity in terms of pain and blistering 2.
- The treatment can be repeated every two weeks for a maximum of 3 months 3, 4.
- It is essential to include a margin of 2 mm around each wart to ensure effective treatment 5.
- For plantar warts, a double freeze-thaw cycle can be used, and the wart can be pared before treatment 5.
Efficacy of Cryotherapy
- Cryotherapy with liquid nitrogen is an effective treatment for cutaneous warts, with cure rates ranging from 39% to 64% 2, 3.
- The efficacy of cryotherapy is higher for common warts than for plantar warts 3.
- Cryotherapy is more effective than topical salicylic acid application for common warts, but not for plantar warts 3.
- Imiquimod 5% cream combined with a keratolytic lotion can be used as an alternative treatment for cutaneous warts in children, with similar efficacy to cryotherapy 4.
Application Methods
- Liquid nitrogen can be applied using a cryo-spray or a cotton wool bud, with similar efficacy 5.
- The choice of application method may depend on the location and size of the wart, as well as the patient's preference and tolerance for pain.