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Mohs Fellowship Trained Surgeon

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About Photodynamic Therapy (PDT)

Photodynamic therapy (PDT) treats early skin cancer

Valley Skin Institute is proud to offer photodynamic therapy (PDT). This innovative dermatology treatment specifically targets and destroys precancerous skin damage.

It combines the application of topical medication that is absorbed by precancerous cells, then activated by a special blue or red light source to destroy sun damage.

Pre-cancer lessions called actinic keratoses, and certain other types of early cancer cells can be eliminated with PDT. Acne can also be treated as well, although this is usually not covered by insurance.

The 3 Steps of PDT

  1. A light-sensitizing liquid, cream, or (photosensitizer) is applied to the area being treated

  2. There is an incubation period (several minutes up to an hour)

  3. The skin is exposed to a specific wavelength of light that then activates the photosensitizing medication. This destroys the bad tissue.

Pdt Fresno

PDT Frequently Asked Questions

How does photodynamic therapy work?
PDT works by direct injury to the target cells and tissues. This involves the production of an activated oxygen molecule that can destroy abnormal cells. It will not harm “normal” cells. With traditional cryosurgery (freezing with liquid nitrogen), only the visible actinic keratoses can be treated. Since many actinic keratoses are often not evident, PDT is a field treatment and can treat subclinical lessions. PDT allows for treatment of an entire area of sun damage simultaneously, but subsequent treatments may be necessary.
What is a typical skin PDT session like?
In the treatment room, you may be sitting or comfortably lying back on a table. Often a thorough cleansing of the face is done using alcohol and or acetone to degrease the skin. The photosensitizer liquid or cream is applied topically to the whole area being treated (such as the entire face, scalp, back of the hands, etc) The medication is allowed to air dry for a few minutes, and then you will wait anywhere from 30-60 minutes to 18 hours, depending on skin pigmentation and anatomical site. PDT requires physician adjustments for specific individualized incubation times and treatment durations. After the proper incubation time, you are exposed to the light source. There may be sensations of warmth, tingling, heat, or burning in some patients. A fan can be used to help cool off during the treatment. The treatment area is then washed off and sunscreen applied. Instructions are given on how to care for the skin at home.
What are the advantages with photodynamic therapy for treating actinic keratoses?

The greatest advantage of PDT is the ability to selectively treat an entire area of skin damage and precancerous actinic keratoses (blanket or field treatment). PDT generally decreases the likelihood of lighter or darker skin spots (post-inflammatory hyper- or hypopigmentation) caused by routine freezing with liquid nitrogen. Additionally, PDT frequently may facilitate smoother skin and an overall improved appearance, tone, color, and enhanced skin texture.

In several studies, PDT has been preferred by many patients for ease of use and rapid recovery as compared to alternative treatments including freezing and topical fluorouracil (Efudex). The PDT side effects may be milder with less downtime than with fluorouracil.

For patients with many skin lesions, PDT may be generally more effective than repeated spot treatment with topical liquid nitrogen. Some patients are unable to tolerate the prolonged treatment required with fluorouracil or imiquimod (Aldara) because of the irritation, redness, and possible downtime with these topical creams. PDT is very well-tolerated, noninvasive (no needles or surgery required) procedure to help reduce sun damage and enhance the overall cosmetic outcome (particularly in sensitive areas of the face and chest).

How much improvement can I expect with photodynamic therapy?
No two individuals are the same, and results may vary. Some conditions can improve dramatically in some patients and not respond in others. Overall, patients with severely sun-damaged skin with actinic keratosis, mottled pigmentation, dull or sallow skin, and skin laxity, may see good to excellent improvement with PDT. There can be improvement of large pores, non-pitted acne scars, and active acne. Depending on the area being treated and the recommended incubation time, different numbers of treatment sessions spaced 4 to 6 weeks apart may be required to achieve the desired improvement and reduction in lesions. On average, a series of two to three treatments are performed. It is not always possible to predict ahead of time how many treatments your specific condition may take or how you will respond to PDT.
Is PDT right for me?
Ideal candidates for PDT usually have lighter or fair skin that exhibits sun damage, particularly scaly spots called actinic keratosis. You may not be a good candidate if you are sensitive to light or taking any type of medication that might bring on skin irritation during light-based therapies. You may also not be eligible if you have certain medical conditions such as systemic lupus erythematosus or porphyria. During your initial consultation, we will review your medical history to determine if this treatment is right for you.
Will PDT make me permanently more sensitive to light?

No, PDT causes a temporary sensitivity to light, including natural sunlight and some indoor lights. The light sensitivity resolves with time, depending on both the photosensitizer drug and dosage used.

Light avoidance is generally required after PDT. The duration depends on the drug and dosage used.

What are the potential side effects

Most patients tolerate the minor procedure very well without any complications. Since an exaggerated light-sensitive reaction is expected by definition of PDT, most patients understand and expect some type of a sunburn or red reaction after skin PDT. However, some patients may have no visible reaction or redness.

Possible risks and complications of PDT include burning of the treated area, skin discoloration, skin redness, prominent tiny blood vessels (telangiectasia), pain, infection, cold-sore activation, blisters, scabs, unsightly scars, cosmetic disfigurement, skin discoloration, eye injury or swelling, allergic reactions, prolonged sun sensitivity, and reaction to topical anesthesia.

Minor, serious, or life-threatening reactions can occur with the use of anesthetics or with medications given before, after, or during a procedure.

Is there scarring from photodynamic therapy?

No, PDT usually does not leave scars in typical cases. Overall when you undergo PDT, there will be some type of a red skin reaction and irritation for 3 to 10 days after the treatment. Some people are more sensitive to PDT and the light treatment than others. Similarly, some people heal better or faster than others. Some residual redness may be more noticeable depending on the location and skin type. Some people may have temporary skin discoloration that may last weeks to months. Patients with darker skin types may have more skin discoloration after treatment.

Does insurance cover PDT?

Photodynamic therapy is currently considered a medical service for the treatment of some conditions, particularly for actinic keratosis. However, it may be considered cosmetic, or not medically indicated for conditions for which it is regularly used.

Contact your insurance carrier prior to scheduling any treatment and confirm your eligibility and benefits.

If you have skin that has been damaged from precancerous skin cells or severe sun damage
Photodynamic therapy (PDT) may be the answer to healthier skin This restorative LED light therapy treatment can target superficial skin cancers called actinic keratoses.

Before and After Photodynamic therapy (PDT)

Before PDT


  • If you are prone to cold sores, you will be given a prescription for Valtrex, an Antiviral drug. Start taking Valtrex, two days before treatment.
  • You may take 1 to 2 Benadryl before your treatment to help with the itching and burning that may results, but you will need a driver if you do so.
  • Most patients continue all prescribed medications, including aspirin and any blood thinners unless specifically advised otherwise only by the doctor.

Prepare your skin

  • Do not shave on the day of treatment
  • Your skin should be thoroughly clean and free of all makeup, moisturizers, and sunscreens. 
  • Wear comfortable casual clothes and

Covering your skin

  • You should bring gloves or a long-sleeve shirt if having hands or forearms treated.
  • Bring a wide-brimmed hat for facial or scalp treatments. 

Prepare your body

  • Do not smoke for three days before and two weeks after your PDT procedure. Smoking can slow down wound healing and cause an increased risk of wound infections.
  • Do not drink alcohol for three days before PDT; it can cause more bleeding and thin your blood.

Perpare your mind

  • Since you will be in the office for at least an hour, you may want to bring something to pass the time.


On the day of treatment

  • Begin applying ice packs to the treated area for ten minutes at a time for 24-48 hours. This will help alleviate discomfort and reduce swelling.
  • Swelling will be most evident around the eyes and is usually more prominent in the morning.
  • You may spray on a thermal spring water such as Evian or put cold water in a spray bottle. This will keep the heat under control.
  • Wash, moisturize and apply a sunblock. The staff will give you recommendations on products to use.
  • You may take 1 to 3 Benadryl (25-50 mg) to relieve itch and pain which will likely make you sleepy.

DAYS 2-7

  • Wash your face twice a day with Cetaphil, Fig Gentle Cleanser (available in the office) or Dove Sensitive Skin.
  • Generously apply Aquaphor or Vaseline Jelly a few times a day – your face should be goopy.
  • After a few days, your face will peel. While it is peeling, continue using the Vaseline Jelly- this will help it heal faster.
  • You may shave at any time but it may more comfortable to wait until after you have peeled.
  • You may begin applying make-up once any crusting has healed.
  • The skin will feel dry and tightened. Repeat application of moisturizer helps
  • Avoid direct sunlight for one week.
  • Whenever you go out, you must wear a physical sunscreen such as Cetaphil, Neutrogena Pure and Free, Vertra, Aveeno, Fig Sunscreen sold at the office
Note: The area may be red for 1-2 weeks. Do not pick or scrub your skin, it can cause severe irritation or scarring. Contact our office if your pain is increasing one to two days after your procedure or if you have a fever or other concerning symptoms.
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