Cantharidin, the active ingredient in Cantharone, is a potent blistering agent derived from the dried, powdered blister beetle. This “blister beetle juice” is commonly used to treat warts and molluscum, especially in children for whom other treatment options may be too painful, traumatic, or frightening.
Cantharone is carefully applied by the provider, allowed to dry, and occluded by a strip of paper tape. It is removed with soap and water after a period of time depending on the type of wart, size, and location. Depending on the reaction, the length of time until the Cantharone is removed may need to be increased or decreased at future visits. Cantharone usually produces a blister which then dries and peels off removing part of the wart in around 10 days.
Although most patients note little discomfort, some may experience tingling, itching, or burning. The area may be tender for several days. Acetaminophen or ibuprofen may be given for discomfort. Soaking the area with cool water compresses may also provider relief. If present, a blister may be punctured with a sterile needle if it is uncomfortable. Otherwise, leave the blistered skin intact to provide a natural Band-Aid.
It is not uncommon to need repeated treatments and although highly effective, Cantharone will not work for all warts. Appointments should be scheduled at 3-4 week intervals for optimal results.
Please wash the treated areas with soap and water in 4 hours. Remove earlier if stinging or burning occurs before this time.
Please call the office if you have any questions about your therapy.