When is topical 5-fluorouracil recommended for Bowen's disease?

Bowen's disease, also called squamous cell carcinoma in situ, is an abnormal growth limited to the outer skin layer. It may look like a persistent red, scaly, crusted, or sharply outlined patch. Diagnosis and depth matter: a clinician may examine the area closely or take a biopsy before choosing cream treatment.

Topical 5-fluorouracil acts on abnormal surface cells in the prescribed area. The skin may become inflamed, sore, crusted, or temporarily more noticeable while treatment is working. Cream treatment is not suitable for every lesion, particularly when a spot is thick, invasive, or in a location needing a different approach.

Follow the exact application instructions and treat only the area your dermatologist identifies. Keep the cream away from the eyes, mouth, and broken skin unless specifically instructed. Protect the site from sun exposure, avoid picking crusts, and use only recommended soothing products. Attend the planned review so the clinician can assess whether the lesion has cleared.

Ask about alternatives such as a procedure, freezing, or another prescribed treatment if the lesion is thick, recurrent, or difficult to treat with cream. Further information is available in [Topical 5-Fluorouracil](/treatments/medical-dermatology/topical-5-fluorouracil/).

Contact the clinic if pain, swelling, blistering, or ulceration becomes difficult to manage, or if you cannot tell whether the skin reaction is expected. Request prompt assessment for a growing lump, persistent bleeding, increasing tenderness, or an ulcer that does not heal. These changes can signal that the lesion needs a different assessment or treatment.

Ask whether the diagnosis was confirmed, why cream is suitable for this lesion, what reaction is expected, and when healing should be checked. Ask what signs would mean the treatment needs to be paused or reviewed.