Hi @leper! We took your questions to a pharmacist here at Mayo Clinic. She writes:

"Efudex is a very powerful medication. It is not typically used long term. Most courses of treatment last 2 to 4 (sometimes 6) weeks if treating actinic or solar keratosis, and up to 12 weeks for superficial basal cell carcinoma. It is important to wear a glove when applying it and/or washing hands immediately after application. Common side effects include: scaling at the application site, dryness, crusting, skin erosion, redness, stinging, burning, itching, swelling, and pain. The side effects may last for several weeks after stopping the medication. It will also cause you to be even more sensitive to sun leading to severe sunburn, so use additional care while outside.

The side effects are intense and most occur in at least half (scaling, dryness, and redness occur in about 95-99% of patients), but the medication is widely used and works well.

The best way to avoid needing it again in the future is to use high SPF sunscreen on a daily basis, even when going outside for a short amount of time. I hope the treatment goes well for you with minimal side effects."

I hope you find this information helpful and empowering.

It sounds like you love being outside. Do you have any tips for protecting your skin from the sun that others may benefit from? Any particular sunscreen you really like?