What does photodynamic therapy treat?

A photosensitising medicine is applied to the skin or used according to the treatment plan, then activated with a specific light. The reaction targets abnormal cells near the treated surface. Dermatologists may use it for [Actinic Keratosis](/conditions/actinic-keratosis/), [Actinic Cheilitis](/conditions/actinic-cheilitis/), selected superficial [Basal Cell Carcinoma](/conditions/basal-cell-carcinoma/), or [Bowen's Disease](/conditions/bowens-disease/).

Suitability depends on the lesion’s depth, location, appearance, and whether a biopsy or another treatment is needed. It is not a general treatment for every skin cancer or every rough patch.

Your clinic will explain how to prepare the area and how long to protect it from bright light after treatment. Burning, stinging, redness, swelling, crusting, or temporary tenderness can occur as the treated area reacts. Follow wound-care instructions, avoid picking crusts, and use only recommended products.

Tell your clinician about medicines and conditions that increase light sensitivity. Ask whether [Topical 5-Fluorouracil](/treatments/medical-dermatology/topical-5-fluorouracil/) or another approach may fit the lesion better.

Contact the treating clinic if pain is severe or worsening, redness spreads beyond the expected area, drainage develops, or healing is delayed. Seek urgent help for facial swelling affecting breathing, widespread blistering, or feeling seriously unwell.

Ask what diagnosis is being treated, whether a biopsy is needed, how to protect the area from light, what healing changes are expected, and when the site should be reviewed.