Photodynamic Therapy

Photodynamic Therapy (PDT)

Photodynamic therapy (PDT) is a non-surgical procedure that involves the application of a photosensitising agent known as aminolevulinic acid (ALA) to the skin’s surface, which is then stimulated by a special light source known as red wavelength light. Exposure to this type of light has no adverse effects on the skin, unlike other wavelengths of light, such as x-ray and ultraviolet, which emit radiation.

Photodynamic therapy (PDT) has many applications and can be used to treat a number of conditions, including:

Cancers

PDT is a nonsurgical, superficial skin cancer treatment, where Metvix (MLA) is applied to the area of the cancer and covered for 3 hours, followed by exposure to a red light to treat the area. After this, two treatments, 2 weeks apart are required.

Acne

PDT is one of the methods used to treat acne. First, ALA creams are applied to the skin. 3 hours later, red light is then used to activate the treatment area. Following this, three treatments, 1 month apart are required.

Actinic Cheilitis

Photodynamic therapy is a useful treatment for sun damaged lips (actinic cheilitis). ALA cream is applied to the skin and 3 hours later activated by relight treatment. Swelling, redness and peeling of the lip, typically lasts up to a week and repeat treatment may be required 12 weeks later, depending on the response.

Sun Spots

PDT is an excellent treatment for solar keratosis of the face. First, ALA/MLA cream is applied to the affected area. 3 hours later, red light is then used to activate the cream. Inflammation of the sunspots can occur and will usually resolve in a week’s time. (Daylight activation of the cream has been done before and has proven to be successful. Please speak to one of our doctors for more information.)

Suitable skin types

PDT is a safe procedure that can be used on all skin types and on any part of the body. Whilst there are no known complications for PDT, we do not perform this procedure on patients who are:

• Pregnant or breast feeding
• Suffer from a rare hereditary disease known as porphyria which results in extreme photosensitivity
• Have used Roaccutane (Isotretinoin) in the past 6 months
• Are prone to keloid scarring

Number of treatments

A patient undergoing PDT treatment for acne will typically have one treatment every 3 or 4 weeks, for a total of 3 treatments. After the third treatment, maintenance will generally consist of one treatment every 3 months. For some patients, only one treatment every 6 months may be required.

Side effects

PDT causes your skin to become highly sensitive to sunlight for around 48 hours after the procedure, so it’s strongly advised to avoid sunlight where possible and apply sunscreen to help prevent sunburn during this time. Directly following the treatment, some patients may experience some redness and innocuous swelling, akin to minor sunburn. The reddish appearance of the treated skin will typically last for one to two weeks. During the first week immediately following your treatment, your skin may feel taut and dehydrated and there may be some peeling.

Advantages of PDT

Unlike other acne treatments such as Roaccutane, PDT carries no chronic or enduring side effects. Medication such as Roaccutane can leave long-term users vulnerable to a whole litany of adverse complications. PDT on the other hand, only causes minor, temporary discomfort to the patient, while delivering remarkable results.