When is topical 5-fluorouracil recommended for actinic cheilitis?

Actinic cheilitis is sun damage affecting the lip, often causing persistent dryness, scaling, roughness, or a blurred border between the lip and surrounding skin. The medicine is a prescribed cream that targets abnormal, sun-damaged cells in the treated area. A clinician chooses it after examining the lip and may consider a biopsy if the appearance is uncertain or a thicker spot needs assessment.

During treatment, the lip can become red, sore, crusted, or swollen as the cream reacts with abnormal cells. This visible reaction is expected in many treatment plans, but severe discomfort or an unexpected change should be discussed rather than managed by altering the schedule yourself.

Use the cream only on the area and schedule prescribed. Wash your hands before and after application, avoid getting it inside the mouth, and protect the lips from further sun exposure with suitable lip protection. Do not cover the area with a dressing unless your clinician tells you to. Keep follow-up appointments so the response can be checked and any persistent spot can be reassessed.

Ask whether other options, such as a procedure that removes or treats the surface, fit your lip, lifestyle, and examination findings. Read the full treatment guidance for [Topical 5-Fluorouracil](/treatments/medical-dermatology/topical-5-fluorouracil/).

Contact your dermatologist if pain, swelling, blistering, or ulceration makes eating or drinking difficult, or if the reaction seems more severe than you were told to expect. Arrange prompt assessment for a firm lump, a sore that does not heal, repeated bleeding, or a new thickened area on the lip. These features need examination because actinic cheilitis can coexist with a more advanced lesion.

Ask which part of the lip should receive the cream, how to handle irritation, whether you need a biopsy, and when the treated area should be reviewed. You can also ask how sun protection and lip care will reduce further damage.