What is Photodynamic Therapy and What's it for?

Photodynamic therapy is a treatment that’s becoming increasingly popular since it’s a safe and fast solution for many skin conditions. Learn all about it here!
What is Photodynamic Therapy and What's it for?

Last update: 07 August, 2021

Photodynamic therapy is a non-invasive treatment used in dermatology. It’s commonly used to treat cancerous and precancerous lesions.

This form of phototherapy has many advantages and uses. In this article, we’ll tell you everything you need to know about it!

What’s photodynamic therapy?

Photodynamic therapy is a treatment dermatologists use to treat skin problems. It consists of administering a photosensitive compound, which is a substance especially susceptible to light, to the area to be treated.

Then, you have to wait an incubation time, in which the cells soak up this substance. After that time, the area to be treated is illuminated with a laser light source.

When the professional lights the area, the photosensitive substance that they previously administered activates. When this happens, it produces oxidative stress in the cells in which it’s found. This ultimately kills the altered cells, which is the purpose of the therapy.

It’s a selective treatment, which means that it only attacks the chosen abnormal cells. This is because the abnormal cells are more capable of absorbing this photosensitive material. In addition, they eliminate it more slowly.

A patient at the dermatologist.

This article may interest you: The Importance of the Skin Microbiome

What’s it for?

Photodynamic therapy is useful to treat different skin conditions. As we mentioned above, it’s mostly useful for genetically altered cells. In other words, for precancerous and cancerous lesions. Here are some of the conditions it’s most effective for:

  • Actinic keratosis.
  • Basal cell carcinoma.
  • Acne.
  • Rosacea.
  • Skin aging is caused by the sun.
  • Hidradenitis suppurativa (HS).

Read on to learn more: The ABCDE Test for Skin Cancer

The process

Before starting, the dermatologist must clean the area to be treated. It must be a deep cleaning, so sometimes they may need to resort to somewhat aggressive procedures.

Once the skin is ready, the dermatologist applies the photosensitizer to the area. There are different types. Depending on the one the dermatologist resorts to, they’ll subject the patient to the treatment for a period of time that can range from 30 minutes to 5 hours.

During that time, the area will be covered with a dressing. This is very important so that the substance they applied doesn’t react to the light. After the allotted time has passed, the dermatologist removes the dressing and washes the area again with soap and water to remove any excess photosensitizer.

After completing these steps, the professional treats the area with the type of chosen light and application, which will mostly depend on the type of lesion to be treated.

A child at the dermatologist.

Is photodynamic therapy painful?

As we mentioned above, this treatment isn’t invasive. In other words, it doesn’t require surgery or incisions. Nevertheless, you must remember that this treatment consists of damaging cells. Although the most affected cells will be the abnormal ones, the treatment will also affect healthy ones.

This is because a certain amount of photosensitizer can affect the area around the lesion. Therefore, after photodynamic therapy, the area may look irritated and swollen. In that case, the patient may feel pain and burning during the treatment.

Advantages and disadvantages of photodynamic therapy

In conclusion, we must emphasize once again that this is a non-invasive therapy. It can help patients avoid surgery and all the risks it entails. In addition, it’s proven to be very effective in the treatment of precancerous lesions, as it can eliminate 90% of them.

On the other hand, one of its disadvantages is the cost of these photosensitizing substances. In addition, some patients require several sessions to completely eliminate the lesion, which can be inconvenient for them.

Despite this, it’s becoming increasingly popular, since its advantages outweigh its risks. It’s a safe and fast solution for many skin conditions.

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  • Fernández-Guarino M, García-Morales I, Harto A, Montull C, Pérez-García B, Jaén P. Terapia fotodinámica: nuevas indicaciones. Actas Dermosifiliogr. 2007 Jul 1;98(6):377–95.
  • Gilaberte Y, Serra-Guillén C, De Las Heras ME, Ruiz-Rodríguez R, Fernández-Lorente M, Benvenuto-Andrade C, et al. Terapia fotodinámica en dermatología. Vol. 97, Actas Dermo-Sifiliograficas. Ediciones Doyma, S.L.; 2006. p. 83–102.
  • Mordon S, Martínez-Carpio PA, Vélez M, Alves R, Trelles MA. Terapia fotodinámica (PDT) en piel y estética: Procedimiento, materiales y método en base a nuestra experiencia. Cir Plast Ibero-Latinoamericana. 2012 Jul;38(3):287–95.
  • Terapia fotodinámica (PDT) en piel y estética: procedimiento, materiales y método en base a nuestra experiencia [Internet]. [cited 2020 May 19]. Available from: http://scielo.isciii.es/scielo.php?script=sci_arttext&pid=S0376-78922012000300012