All you need to know about phototherapy

Generally, skin diseases tend to diminish, or even disappear, with the arrival of the summer period without you having to treat them. However, there are instances where a few hours in the sun are not enough to resolve the issue, hence the need for phototherapy. This term refers to any treatment of skin diseases using light. This process utilises light or ultraviolet rays to treat certain skin conditions, such as psoriasis and eczema. There are two types of phototherapy: the PUVA therapy which involves exposing the patient in a cabin to UVA rays and the phototherapy with UVB which uses ultraviolet rays closer to those of the sun.

Some conditions need to be considered to avoid problems that may be associated with phototherapy.

• An examination of any potential risk lesions present on your skin should be conducted, regardless of whether they are large or small.

• A skin assessment is equally essential to understand your sun exposure and UV radiation habits.

• An individual whose skin has already been damaged cannot undergo phototherapy.

• An individual undergoing a specific treatment related to the use of a photosensitiser should also refrain.

• In the case of phototherapy, it is necessary to take a psoralen tablet, a photosensitising agent, two hours before the session to enhance the effectiveness of the treatment. Wearing sunglasses is mandatory during the session and for several hours afterwards.

Stress, skin trauma, the use of certain medications, and the application of unsuitable skincare products can lead to skin diseases. Exposing the skin to ultraviolet radiation can be used to treat skin conditions. The phototherapy sessions:

• They help to reduce conditions such as psoriasis, rosacea, or even acne.

• Reduce the redness and inflammation that prevent you from living peacefully on a daily basis.

• Diminishes stretch marks and scars.

Phototherapy may resemble tanning, but the treatment only utilises the 311 nm spectrum ultraviolet ray during sessions. The duration of light exposure is brief, it is conducted under supervision and takes place in a suitable location such as a clinic. Exposures to the rays are done at intervals of approximately 24 hours to avoid sunburn. The frequency of sessions is two to four times per week. You can treat your entire body or expose limited areas (local phototherapy) such as the hands or the scalp.

Phototherapy can generate some short-term undesirable effects, notably:

• Feelings of warmth, the emergence of redness or sunburn (erythema) are immediately noticeable. This could be due to the consumption of a photosensitising food or medication in the case of UVB phototherapy.

• Skin dryness, the emergence of freckles, or skin ageing can occur over the long term in the event of a gradual increase in radiation exposure.

Phototherapy can also have long-term negative effects such as:

• A cataract: it is prevented by wearing opaque glasses.

• A skin cancer is likely to develop if you do not take action. Its risk of occurrence increases when the number of sessions exceeds 250.

ZANOLLI M. Phototherapy arsenal in the treatment of psoriasis. Dermatologic Clinics (2004).

VREMAN H. J. & al. Phototherapy: Current Methods and Future Directions. Seminars in Perinatology (2004).