How long does topical 5-fluorouracil take to work for Bowen's disease?

The medicine targets abnormal surface cells. Redness, scaling, tenderness, crusting or weeping can develop where it is applied; this reaction can be part of the expected response rather than proof that treatment is failing. The treated patch may take additional time to settle after the application course ends.

Apply the prescribed amount on the prescribed schedule and wash your hands afterwards. Do not extend, shorten or restart the course without the prescriber’s advice. Protect the area from sun, avoid picking crusts, and use only recommended products if the skin becomes sore. Keep follow-up even if the patch appears clearer, because the clinician needs to assess whether abnormal cells have resolved.

Contact the treating clinician if the reaction becomes difficult to manage, spreads beyond the treatment area, or interferes with eating, sleeping or normal activity. Seek prompt assessment for increasing pain, spreading warmth or redness, pus, fever, heavy bleeding, or a sore that is not settling after treatment.

Ask which reaction is expected for your site, when the course should stop, what can be applied for comfort, and when the treated area should be reviewed.