After cantharidin treatment

Cantharidin is a liquid painted onto warts or molluscum. It is painless when applied. Over the next day it causes a blister, which lifts the wart or molluscum off the skin.

Washing it off

Wash the treated areas with soap and water at the time we tell you. As a guide:

• Molluscum: usually after 2 to 6 hours. For children, and for a first treatment, we often start with a shorter time.
• Warts under tape: usually after 24 hours. Remove the tape, then wash.

Wash it off straight away if there is burning or pain before then.

Important

• Do not touch the treated areas until they are washed, and keep your fingers away from your eyes, mouth and genitals.
• Keep children from scratching or sucking treated areas.
• Avoid baths and swimming until it has been washed off.

What to expect

• A blister forms within 24 to 48 hours. It may be tender.
• Leave the blister alone. If it breaks, wash gently and cover with a bandaid.
• It usually heals in 4 to 7 days, often with a temporary pink or dark mark.
• For discomfort, paracetamol can help.

Sometimes a small ring of new warts forms around the edge of a treated wart. This can be treated at your next visit. Warts and molluscum often need more than one treatment, usually 2 to 4 weeks apart.

When to contact us

• Severe pain, or a very large blister
• Redness or swelling that is spreading
• Pus, a bad smell, or a fever