From the Guidelines
A cryotherapy cycle for wart removal typically lasts 10 to 30 seconds per application, with repeat applications every 1–2 weeks. The process involves applying liquid nitrogen to the wart, freezing the tissue, and then allowing it to thaw before potentially repeating the cycle. This cycle is repeated every 1–2 weeks, as needed, until the wart is removed 1.
The application of liquid nitrogen causes thermal-induced cytolysis, destroying the wart cells and triggering an immune response against the human papillomavirus 1. The healthcare provider must be trained on the proper use of this therapy to avoid complications or low efficacy.
Some key points to consider when using cryotherapy for wart removal include:
- The total number of sessions needed varies depending on the wart's size, location, and type
- Most warts require multiple treatment sessions spaced 1 to 3 weeks apart
- Each session potentially involves 1-3 freeze-thaw cycles
- The wart is frozen until a 1-2 mm white freeze halo appears around the base, then allowed to thaw completely before any subsequent freezing
- After treatment, a blister may form and the treated area may be sore for a few days, which is a normal part of the healing process 1.
It's essential to follow the recommended treatment schedule and guidelines to ensure effective removal of the wart and minimize potential side effects 1.
From the Research
Cryotherapy Cycle Duration for Wart Removal
- The duration of a cryotherapy cycle for removing a wart can vary, with some studies using a single cycle of 10 seconds of freezing 2 and others using a single cycle of 20 seconds of freezing 2.
- Another study used a double freeze-thaw cycle for plantar warts, with liquid nitrogen applied until ice-ball formation had spread from the centre to include a margin of 2 mm around each wart 3.
- The frequency of cryotherapy sessions also varies, with some studies performing treatments every 2 weeks 2, 4, 5 and others every 4 weeks 2.
- The choice of cryotherapy protocol may depend on the type and location of the wart, as well as the patient's individual response to treatment 2, 4, 3, 5.
Factors Influencing Cryotherapy Efficacy
- The efficacy of cryotherapy for wart removal can be influenced by factors such as the duration of the wart, with warts present for 6 months or less having a greater chance of clearance 3.
- The number of warts and their location can also impact treatment outcomes, with common warts on the hands and feet responding better to cryotherapy than plantar warts 2, 4.
- The use of different applicators, such as a cotton wool bud or cryo-spray, may not significantly affect treatment outcomes 3.
Comparison with Other Treatments
- Cryotherapy has been compared to other treatments for wart removal, including salicylic acid application 4, cantharidin-podophylotoxin-salicylic acid 5, and other destructive therapies 6.
- The efficacy of cryotherapy relative to these other treatments can vary depending on the specific study and patient population 2, 4, 5, 6.