How effective is topical 5-fluorouracil for actinic cheilitis?

Actinic cheilitis is sun-related damage affecting the lip, often causing dryness, scaling, roughness or a blurred border. 5-fluorouracil targets rapidly dividing abnormal surface cells. As those cells respond, the treated lip may become red, sore, crusted or more sensitive before it settles.

The medicine is not appropriate for every lip change. A thick area, ulcer, bleeding point or persistent focal lesion may need examination and sometimes sampling to exclude an invasive cancer. Treatment response can be incomplete, and follow-up helps identify remaining or returning abnormal areas.

Use the medicine only in the strength, amount and schedule prescribed for your lip. Do not extend the course or apply it to broken skin without instructions. Protect the lips from sunlight with a suitable lip product and avoid picking crusts or adding irritating cosmetics during treatment.

Ask how to wash hands after application, what to do if the medicine reaches the mouth, and which moisturiser or pain-relief measures are compatible. Keep the review appointment even if the surface looks better, because a clinician may need to check the entire lip border.

Contact your prescriber for severe pain, marked swelling, spreading blistering, signs of infection, difficulty eating or drinking, or a reaction beyond the treated area. Seek prompt assessment for a persistent ulcer, lump, bleeding site or one-sided thickening of the lip.

Ask whether the diagnosis is confirmed, how the reaction should look, when to pause or stop, how sun exposure should be handled, and what will happen if a rough area remains after treatment.