What to expect from topical 5-fluorouracil for actinic cheilitis

5-fluorouracil is applied to the lip area identified by your clinician. It interferes with abnormal, sun-injured cells, so the treated skin can become more inflamed before it improves. The reaction is not a sign to increase the amount or apply it more often. Actinic cheilitis can resemble other lip conditions, and a persistent thickened, bleeding, ulcerated, or tender spot may need reassessment rather than repeated self-treatment.

Use only the prescribed amount and schedule, with clean, dry hands. Keep the medicine away from the inside of the mouth and eyes, and wash your hands after application. Avoid picking scale or crusts. Use a lip product and sun protection recommended by your clinician, because ultraviolet exposure can continue to irritate the area. Do not add steroid creams, antiseptics, or cosmetic products unless the prescriber approves them. Keep follow-up appointments so the response can be checked after the course.

Contact the prescriber if pain prevents eating or drinking, swelling spreads beyond the treated lip, or the reaction seems far more intense than discussed. Get urgent help for facial swelling with breathing difficulty. Arrange a review for a sore, lump, bleeding point, or ulcer that remains after the expected healing period, because treatment may not have addressed every abnormal area.

Where exactly should I apply the medicine, and what reaction should I expect at each stage? What should I use for comfort and sun protection? When should I pause treatment, and when will you check whether a persistent spot needs another assessment?