Psoriasis Light Therapy

Light therapy for psoriasis is a scientifically recognized procedure used worldwide that has achieved great success. So-called psoriasis vulgaris is a chronic inflammatory disease of the skin that progresses in episodes and is based on a genetic disposition. The disease can be triggered by physical, chemical, mechanical and inflammatory irritations of the skin as well as by infections, HIV disease, pregnancy, medication or stress.

Externally, itchy, reddened, sharply demarcated, scaly papules appear, which are caused by an excessive formation of the epidermis (top layer of skin). The human epidermis consists of seven layers, whose cells are characterized by different stages of maturation. During a period of approximately 28 days, the cells migrate from the basal layer up to the corneal layer, changing their morphology (shape) before detaching as skin scales. In psoriasis vulgaris, this process occurs within 4 days and leads to the symptoms described. This occurs preferentially on the following areas of the body:

  • Stretch sides of the arms and legs (eg, knees or elbows).
  • Hand and foot insides
  • Lumbar region
  • Hairy head area

In addition to the aforementioned symptomatology, changes in the nails called onycholysis semilunaris psoriatica or oil spot nails may occur. Other changes are spotted nails (small retractions on the surface) or crumb nails.

All in all, psoriasis vulgaris is a disease that causes high psychological suffering in those affected. Light therapy can positively influence this condition.

The procedure

Ultraviolet light is used for the treatment of psoriasis. There are several therapeutic options, which are presented below:

  • Broad-spectrum UVB – In this somewhat older procedure, the patient is irradiated with the full spectrum of UVB light (280-320 nm). A variation of this treatment is also known as selective UVB therapy (SUP), where some UVB lamps can change the light settings.
  • Narrow-spectrum UVB/ 311-nm UVB – This form of therapy is considered the most important in the treatment of psoriasis, as its efficacy is best proven. After determining the MED (the minimum erythema limit is defined as the radiation intensity that causes just visible erythema (redness), which is considered a measure of the intensity of therapy), therapy is started.
  • PUVA therapy – This term stands for the combined use of UVA light (UV-A phototherapy) and psoralen. Psoralen are substances that have a photosensitizing (increase photosensitivity) effect on the skin, so that the effectiveness of UVA light is increased. In Germany, the substance 8-methoxypsoralen (8-MOP) is used. This substance can be applied via oral therapy (tablet administration; oral PUVA therapy/oral puva), although bath PUVA treatment and cream PUVA treatment are also available today. This procedure is also known as photochemotherapy.

Light therapy for psoriasis should not be used excessively, as sunburns can occur and the risk of skin cancer increases with increasing exposure to light.

Benefits

Treatment of psoriasis vulgaris with light therapy is a procedure that is part of standard therapy and is an important treatment due to its effectiveness.