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PUVA: definition, field of application, process and risks

by Josephine Andrews
Published: Last Updated on 451 views

With PUVA , the skin is first treated with a light sensitizer (psoralen). This natural substance sensitizes the skin to the subsequent irradiation. Only then does UV-A phototherapy follow. Read all about the PUVA, how the procedure works and what the risks are.

What is a PUVA?

PUVA stands for psoralen and UV-A phototherapy and is a variant of light therapy . The psoralen, a natural substance found in the essential oils of various plants, sensitizes the skin and makes it more sensitive to the subsequent UV-A radiation. There are two forms:

Topical PUVA therapy

With topical PUVA therapy, only the affected skin areas are treated with the psoralen. Smaller areas are coated with a psoralen-containing cream that is absorbed under a foil. An alternative is the bath PUVA, in which the psoralen accumulates in the warm water bath during the bath in the skin.

Systemic PUVA therapy

With systemic PUVA therapy, the psoralen is distributed throughout the body. For this purpose, the patient takes psoralen tablets two hours before the UV-A radiation.

When do you do a PUVA?

The PUVA is one of the most effective forms of light therapy. Neurodermatitis , psoriasis (psoriasis) and lichen planus (lichen planus) respond particularly to the cream or bath PUVA. Systemic PUVA is primarily used in chronic cutaneous T-cell lymphoma and vitiligo . Other dermatological conditions may also benefit from this form of light therapy. However, despite opposing opinions, acne is not one of them.

What do you do with a PUVA?

Before the actual PUVA therapy, the doctor rules out increased sensitivity to light caused by medication or malignant skin tumors. It also determines the so-called minimum phototoxic dose (MPD). It indicates the UV dose from which the skin with a photosensitizer shows reddening. After the psoralen has taken effect, only 20 to 30 percent of the MPD is irradiated in the first session and the dose is slowly increased. During the entire UV-A phototherapy it is necessary to wear special glasses to protect the eyes. The treatment is always given on two consecutive days with a one-day break. Ten to 30 sessions are usually necessary.

What are the risks of a PUVA?

The PUVA is a very effective but also intensive light therapy. Skin and eyes should be particularly protected during and after treatment due to the following risks:

  • possibly carcinogenic effect by the UV light
  • phototoxic reaction – a kind of sunburn due to increased light sensitivity
  • photoaging of the skin
  • sunburns
  • Inflammation of the conjunctiva (conjunctivitis) and inflammation of the cornea (keratitis)
  • Liver spots (Lentigines)

What do I have to consider after a PUVA?

The skin remains very sensitive to the psoralen for around three to four hours with topical PUVA and for at least twelve hours with systemic PUVA . Consistent skin protection and wearing protective glasses against UV radiation are necessary after the treatment, even in closed rooms, since UV light can also penetrate through window glass.

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