Photodynamic therapy (PDT)

Photodynamic therapy combines a light-sensitising medication, oxygen in the tissue, and a light source to destroy abnormal skin cells while largely sparing normal ones.

It is used at Me Clinic for sun-damaged skin, certain precancerous and superficial skin cancer lesions, acne and pigmentation.

PDT is a medical treatment, not a cosmetic facial. The aftercare - particularly light avoidance - is stricter than for most skin treatments, and it matters.

How it works

A photosensitising agent is applied to the skin. The most commonly used is aminolevulinic acid (ALA), applied topically.

Abnormal and damaged cells take up and concentrate the agent more than normal cells do. When light of a specific wavelength - red or blue - is then shone on the area, the agent absorbs it and reacts with oxygen in the tissue, producing reactive oxygen species that destroy the cells holding it.

The selectivity comes from that differential uptake: the medication concentrates where the damage is, so the light destroys diseased and damaged cells rather than healthy skin.

Red light penetrates more deeply and is generally used for deeper lesions and severe acne. Blue light is more superficial and is generally used for surface lesions and mild to moderate acne.

What it is used for

Sun damage and precancerous lesions

PDT is used to treat actinic (solar) keratosis, and certain superficial skin cancers including Bowen's disease (squamous cell carcinoma in situ) and superficial basal cell carcinoma.

An advantage in these cases is that it treats a whole field of sun-damaged skin rather than one lesion at a time - useful where there is widespread damage with multiple lesions at different stages.

This is a treatment for diagnosed lesions, not a substitute for a skin check. Any lesion should be assessed - and where appropriate biopsied - before it is treated. Not every skin cancer is suitable for PDT; invasive and deeper cancers require excision.

Acne

PDT shrinks the sebaceous (oil) glands that drive acne, reduces the bacteria involved, and reduces inflammation. Over a course of sessions this can produce fewer inflamed lesions and a more even skin texture.

Sun spots, pigmentation and skin ageing

Treating a field of sun-damaged skin also improves the appearance of pigmentation and texture in that field.

The procedure

The treatment area is gently scraped to remove dry and scaling skin, so the medication can be absorbed evenly.
The photosensitising agent is applied.
An incubation period of three to six hours follows while the agent concentrates in the target cells. This is why PDT is a longer appointment than most skin treatments.
Light is applied to the area for 5 to 45 minutes, depending on the light source and the condition. This part can be uncomfortable - stinging or burning during illumination is common and is managed with cooling and breaks.
The area is covered with a dressing.

PDT can be performed on any area a light source can reach.

How many treatments

We usually recommend one to five treatments, ideally spaced four weeks apart. Milder treatment settings may require more sessions but generally involve a shorter healing time - a trade-off discussed at consultation.

Aftercare - this part is not optional

For a period after treatment your skin remains photosensitised. Sunlight, and even bright indoor light, can trigger a strong reaction.

Stay indoors as much as possible for the first three to four days.
Wear SPF 30+ sunscreen whenever you go outside.
Cover the treated area with a dressing or clothing for extra protection.
Wear a broad-brimmed hat if your face was treated.
Do not pick scabs or peel skin as the area heals.
Use a cold compress and simple pain relief for discomfort.
Apply a petroleum-based ointment for further relief.

Expect the treated area to look worse before it looks better: redness, swelling, crusting and peeling over roughly a week are the normal course of a treatment that has worked as intended.

Risks

Stinging, burning or pain during light exposure - often the most uncomfortable part
Redness, swelling, crusting and peeling afterwards
A severe phototoxic reaction if the treated skin is exposed to sunlight or bright light during the photosensitive period
Blistering
Changes in pigmentation - darkening or lightening, which may persist
Scarring
Infection
Allergic or contact reaction to the photosensitising agent
Incomplete clearance of a lesion, requiring further treatment or a different approach
Recurrence

Contact the clinic for increasing pain, spreading redness, pus or fever during healing.

Please read our information on the risks and complications of cosmetic surgery before proceeding.

Cost and booking

Cost depends on the number of sessions required and your individual circumstances, and is quoted at consultation. Where PDT is performed as treatment for a diagnosed skin lesion rather than for cosmetic reasons, a Medicare rebate may apply in some circumstances - your doctor will advise.

As at September 2024 and including GST, a skin assessment with a nurse or aesthetician is $50 and is redeemable on products or services; a consultation with a Cosmetic Doctor is $150.

Me Clinic is at 4 Burke Road, Malvern East VIC 3145. Phone 1300 852 050.

See laser skin rejuvenation, IPL, skin cancers, mole removal, or all face procedures.

Individual results may vary. Any surgical or invasive procedure carries risks. Before proceeding you should seek a second opinion from an appropriately qualified health practitioner.