Plantar warts are common, noncancerous skin growths on the soles of the feet. These rough, cauliflower-like bumps are caused by specific strains of the human papillomavirus (HPV) entering through small cuts or breaks. Due to their location on weight-bearing areas of the foot, plantar warts can cause discomfort or pain, making walking difficult. For many seeking relief, freezing, known as cryotherapy, is a common method for their removal.
How Freezing Works
Cryotherapy involves applying extreme cold to the wart tissue to destroy it, typically using a very cold substance such as liquid nitrogen or a mixture of dimethyl ether and propane. When applied, the intense cold causes ice crystals to form inside the wart cells. These crystals disrupt cell membranes and internal structures, leading to cell death. Freezing also impacts the small blood vessels supplying the wart, cutting off its nutrient and oxygen supply. The tissue damage initiates an inflammatory response, stimulating the body’s immune system to recognize and fight the HPV responsible for the wart. This combined action aims to remove the wart and encourage the body’s natural defenses to clear any remaining viral particles.
Home Versus Professional Freezing
Freezing methods vary significantly between professional medical settings and at-home applications. Healthcare professionals, such as dermatologists, typically use liquid nitrogen for cryotherapy, reaching temperatures around -196°C (-320°F). This very low temperature allows for rapid and deep freezing of the wart tissue, enhancing its effectiveness. In contrast, over-the-counter (OTC) kits for home use contain cooling agents, most commonly a mixture of dimethyl ether and propane (DMEP), which achieve less cold temperatures, generally -57°C to -80°C. While accessible, the lower temperature and less precise application of home kits may result in less effective penetration and destruction of deeper wart tissue compared to professional treatment. Professional cryotherapy often yields higher success rates, though home options can be a convenient starting point for smaller warts.
What to Expect from Treatment
During freezing, a stinging, burning, or aching sensation is common, and immediately after, the treated area may appear red, swollen, and sore. Within 24 hours of treatment, a blister typically forms over the wart, which can be clear or, at times, may appear blood-filled. Over the next few days, the blister usually resolves, forming a scab, and the wart and scab should then shed, revealing new skin underneath. Complete healing usually occurs within one to two weeks, though multiple sessions, spaced two to four weeks apart, are often necessary to fully resolve the wart.
When Freezing May Not Be Suitable
While freezing is a common treatment for plantar warts, there are instances where it might not be the most appropriate choice. Large or deep warts can be challenging to treat effectively, as the freezing agent may not penetrate sufficiently to destroy the entire lesion. Warts in sensitive areas, such as near the eyes, nostrils, or on the sides of fingers and toes, carry a higher risk of nerve damage. Individuals with certain underlying medical conditions should approach cryotherapy with caution, as those with poor circulation, diabetes, or nerve damage in their feet may experience compromised healing or increased complications. Freezing may also be unsuitable for very young children or those highly sensitive to pain, as the procedure can be uncomfortable. In such cases, or if the wart is undiagnosed, other treatment options, including salicylic acid applications, surgical removal, laser therapy, or immunotherapy, may be recommended after a professional medical evaluation.