Photo Dynamic Therapy (PDT)

Your doctor will first confirm the treatment area. Any rough or scaly skin is gently removed to help the cream absorb properly. A photosensitising cream is then applied:

• ALA cream – absorbs in about 30 minutes
• MAL (Metvix) cream – absorbs over 2 hours

After the incubation time, the area is exposed to a bright treatment light for around 10 minutes (blue light for ALA, red light for MAL). This part can feel warm or stinging, but cooling fans, sprays, and local anaesthetic can help make it more comfortable. You may also take paracetamol beforehand if advised by your doctor.

You must avoid all sun exposure on the day of treatment and for 48 hours afterward to prevent an excessive reaction.

Daylight Photodynamic Therapy (Daylight PDT) is a gentler alternative to traditional PDT. Instead of activating the treatment cream with a bright clinic light, the cream is activated by natural sunlight. This makes the procedure significantly less painful, with most patients describing only mild warmth or tingling. Daylight PDT is ideal for treating large areas of sun damage, such as the face or scalp, and generally results in shorter downtime.

It is performed by applying the photosensitising cream and then spending a set period outdoors in natural daylight, under your clinician’s guidance. Daylight PDT is safe, effective, and a popular option for patients wanting a more comfortable treatment experience.

Your skin will be red, warm, swollen, and may develop crusting over the treated areas. These effects are expected and usually settle over several days. Many patients require 3–7 days off work, especially for public-facing roles.

Compared with other treatments for solar keratoses, PDT generally offers faster healing and less downtime.

The photosensitising cream makes your skin extremely sensitive to light for 48 hours. Even brief sun exposure can trigger a severe reaction, causing excessive burning, redness, and swelling. Staying indoors and keeping sunlight out of your home is essential for safe healing.

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PDT is a highly effective treatment for sun-damaged skin:

• Around 80% of actinic keratoses clear after a single treatment.
• Around 80% of intraepithelial carcinomas (IEC/Bowen’s disease) clear after two treatments.

Because only certain areas of the face can be safely treated at one time, you may need multiple sessions. Sun-damaged skin can also form new lesions over time, so repeat treatments are common in future years.

PDT is highly effective for treating sun-damaged skin and certain superficial skin cancers.

• Actinic keratoses (solar keratoses): Around 80% clear with a single PDT treatment.
• IECs (Intraepithelial Carcinomas/Bowen’s disease): These are very early, superficial forms of squamous cell carcinoma that sit in the top layer of the skin. They typically require two PDT treatments, with around 80% achieving clearance.

Because only part of the face or scalp can be safely treated at one time, your treatment may be staged over several sessions. Sun-damaged skin can also produce new lesions over time, so repeat treatments may be needed in the future.

Yes – PDT is safe when performed by trained clinicians.
Temporary side effects may include redness, swelling, crusting, and increased sun sensitivity for a few days. Daylight PDT typically has fewer side effects.