Cantharone® is used by dermatologists for a variety of purposes.  Most commonly, it is used to treat warts or molluscum contagiosum, especially in children.  

What is Cantharone® and How Does it Work?

Cantharone® (canthardin) is a chemical derived from the blister beetle.    When this liquid is applied to warts (or other skin growths), it causes a separation (and blister)  in the skin.  It works by breaking down the bonds that hold the skin cells together.  The top layer of the blister peels off within 1-3 weeks and takes all or part of the original growth with it.  

What are the Side Effects of Cantharone® Treatments?

  • Treatments with cantharone® are painless, which is why this agent is often chosen for the treatment of children.  
  • Blisters typically develop 24 hours after treatment at the sites where the cantharone® was applied.  Sometimes the areas scab slightly rather than blistering.  The blisters can be uncomfortable
  • Sometimes, scabbing leaves the skin lighter or darker than the surrounding skin.  This is usually temporary.
  • It is unusual, although not impossible, for treatments with cantharone® to cause scarring

How Should I Take Care of the Sites where my Child has been Treated with Cantharone®?

  • Cantharone® must be washed off after application.  It is very important to follow your dermatologist's instructions on when to wash the area with soap and water.
  • If blisters develop they can be broken with a sterile needle, if desired.
  • Protect the skin from the sun while it is healing (and always) by wearing sun-protective clothing or a broad-spectrum sunscreen with an SPF of 30 or higher