Warts are common skin growths caused by the human papillomavirus (HPV) that infects the top layer of skin cells. Cryotherapy, often performed using liquid nitrogen, is a standard treatment method that rapidly freezes the wart tissue. This process of freezing and thawing creates localized damage aimed at destroying the wart cells and triggering an immune response against the virus.
Understanding the Immediate Reaction to Freezing
The application of a freezing agent causes an immediate, intense cold sensation, often followed by stinging or burning pain that can last for several minutes to a full day. This sensation is the body’s reaction to the rapid temperature drop, which induces cell death in the targeted area. The destruction of the wart cells is achieved through the formation of ice crystals, which disrupt the cell membranes and internal structures.
Within 24 to 72 hours following the procedure, a blister is expected to form beneath the treated wart. This blister, which can be clear or sometimes filled with blood, signals that the treatment successfully destroyed the targeted tissue. The blister separates the damaged wart tissue from the healthy skin below and acts as a natural protective layer over the wound, initiating the body’s healing response.
The Typical Timeline for Wart Sloughing
The process of the wart falling off, known as sloughing, typically begins after the blister has formed and started to dry out. The most common timeframe for the dead wart tissue to fully detach is between one and four weeks after the cryotherapy session. This period allows the body to complete the inflammatory response and the subsequent repair process.
The exact length of time for sloughing depends on several factors, including the wart’s size, depth, and location on the body. Warts on areas with thick skin, such as the soles of the feet, often take longer to fully separate due to the greater depth of tissue that must be frozen and shed. A more aggressive freeze, sometimes necessary for deep warts, can also lead to a longer healing and detachment period.
As the healing progresses, the blister will dry, harden, and transform into a scab. This scab, which contains the dead wart tissue, will gradually lift away from the underlying healthy skin. The final separation occurs when new, healthy skin cells regenerate beneath the dead layer, pushing the scab and the wart tissue completely off the body.
Caring for the Treated Area While Waiting
While waiting for the wart to detach, over-the-counter pain relievers, such as acetaminophen or ibuprofen, can be used to manage any throbbing or tenderness that may persist for the first day or two after the procedure. The blister should be left intact whenever possible, as the roof acts as a sterile, natural bandage protecting the healing skin underneath.
If the blister breaks on its own, the area should be gently cleaned daily with mild soap and water, then covered with a sterile bandage and petroleum jelly to keep the wound moist and protected. Do not pick at the blister or attempt to forcibly remove the resulting scab or wart tissue. Picking or peeling the dead skin can introduce bacteria, increasing the risk of infection, causing unnecessary scarring, or leading to the spread of the HPV virus. Allowing the wart to fall off naturally minimizes these adverse outcomes.
Addressing Stubborn Warts and Follow-Up Treatments
Cryotherapy is not always a one-time fix, especially for warts that have been present for a long time or are deeply rooted. If the wart remains largely unchanged or is still soft and fleshy after the initial four-week healing period, the treatment may not have successfully destroyed the full depth of the tissue. This indicates the wart is “stubborn” and will likely require a follow-up application.
Dermatologists commonly space cryotherapy sessions about two to four weeks apart to allow the skin to fully heal between treatments and to assess the success of the previous application. Multiple treatments are often necessary because the liquid nitrogen can only penetrate so deeply without causing significant damage to healthy tissue. A second or third application ensures the complete destruction of the viral tissue, which is necessary for the wart to fully clear.
A consultation with a healthcare provider is warranted if there are signs of infection, such as increasing redness, swelling, fever, or pus drainage from the wound. Follow-up is also necessary if the wart persists after two or three cryotherapy sessions, as an alternative treatment method, like prescription topical medications or other destructive procedures, may be needed to achieve complete resolution.