After the first few days of application, the wart will usually turn white in color and may swell due to the burst skin cells and excess water in the tissue. This may resemble a callous. The medication and covering are working to destroy the top layers of wart tissue, giving the white appearance. The prescriber may offer instruction on the proper way to remove this excess tissue. Patients may also be instructed to periodically follow-up with the prescriber for professional debridement (removal of dead skin tissue) of the wart.