Cantharidin is a medication used to remove warts and a viral skin infection called molluscum contagiosum. It is made from the secretions that come from the green blister beetle in combination with salicylic acid. It works by creating a blister just below the wart, which pushes the wart up and away from the underlying tissue, cutting of the blood supply to the wart. As the blister and the wart dry out, they both slough off, leaving fresh, unmarred skin behind. This medicine is for topical use only, and may have side effects.
Common Side Effects
This drug is well tolerated by most people, and when applied properly, is considered safe. Certain side effects may occur with its use, including itching, burning, tenderness of the skin surrounding the wart, tingling, blistering and pain at the site of the application with additional sensitivity. Temporary color change to the skin may occur.
Severe Side Effects
Allergic reactions may occur, including skin rash, swelling of the mouth and throat, hives, problems with breathing, tightness in the chest, chills, fever and swollen glands. These side effects are rare.
Precautions and Contraindications
Avoid using the medicine if you have diabetes or circulatory problems. Avoid using alcohol for several hours after an application of this medication. There is no solid evidence whether Cantharidin passes through to breast milk, so avoid using it when nursing unless absolutely necessary.
Safety and Warnings
Cantharidin has not been approved by the FDA. It is generally used to treat warts that don’t respond to other medicines. It is highly toxic and should only be applied by a health care practitioner. Small areas of skin should be treated at one time to avoid the risk of absorption. If the skin around the wart is exposed to the drug, it should be removed immediately with nail polish remover. There is a slight risk of scarring after the use of this drug. The product contains salicylic acid, which is similar to a compound used in aspirin. Those who are allergic to aspirin should avoid using Cantharidin.