Cantharidin is a medicine that is an extract from a blister beetle. It is used to treat warts and molluscum.
The physician applies a small amount of medicine to the lesions to induce a blister to treat the condition.
Here is how to take care of the area:
1. Wash the treated area using soap and water, no longer than 8 hours after the medication was applied. If significant pain or discomfort occurs before this time, you may cleanse the treatment sites.
a. If the spots have been taped, remove the tape before washing.
2. Let the blisters form. It should naturally crust over and heal, but if it is large and painful, you may drain it with a sterile needle.
3. If there is discomfort from the treatment, you may take acetaminophen (Tylenol®).
4. If the area is open, please keep clean and apply petroleum jelly (Vaseline®/Aquaphor®) with a band aid.
5. The blisters will take about a week to heal. Reminder, it may take more than one treatment for the lesions to resolve, so remnants of the lesion may be noted. On average 3-6 treatments are needed for resolution of the lesions.
6. Post inflammatory pigment alteration after treatment with cantharidin typically will resolve over time, however there is a potential risk for scarring.
Please call our office at (704)784-5901 if you have any questions, feel like the blister is persisting for more than 7 days or if the area continues to drain and ooze.
