How long does photodynamic therapy take to work for Bowen's disease?

The applied medicine becomes active under the treatment light and triggers an inflammatory reaction in abnormal surface cells. The patch may become red, sore, swollen, scaly, or crusted before it improves. That temporary reaction can make the lesion look more prominent, and the early appearance does not establish whether all abnormal cells have cleared.

Bowen's disease is a surface form of squamous cell carcinoma in situ. The clinician considers its size, thickness, site, and borders when choosing treatment and deciding how closely to review it. A persistent patch needs examination rather than reassurance from appearance alone.

Use the wound-care and light-avoidance plan provided by the clinic. Clean the area gently, leave crusts in place, and use only recommended dressings or ointments. Avoid irritating skincare and friction until the surface is comfortable. Attend the planned review, where the clinician can check for residual scale, thickening, or a need for additional treatment.

Get medical advice for severe or increasing pain, spreading warmth and redness, pus, fever, or bleeding that will not stop with gentle pressure. Earlier review is needed if the patch becomes a lump, forms a lasting ulcer, repeatedly bleeds, or remains clearly abnormal after healing.

Ask when the treated patch should be examined, how to protect it from light, how to manage discomfort, and what would make your clinician recommend another procedure or a tissue sample.