Psoriasis

Overview

Phototherapy has been part of the established treatment of psoriasis for many years. The usual form is narrowband UVB irradiation with monochromatic light at a wavelength of 311 nm, in some cases combined with saline baths. It covers the whole body or a large part of it. Before the skin reaches a satisfactory state, more than 40 sessions are not unusual, which adds up to a high overall UV load (cumulative total dose).

The excimer laser takes a different route. The pulsed XeCl laser emits monochromatic light at a wavelength of 308 nm, very close to the spectrum of the established 311 nm devices. Only the affected plaque is irradiated, while the healthy skin around it is spared. Treatment can therefore start at a higher, precisely delivered dose and raise that dose more quickly: the effective total light dose within the psoriasis plaque is around 40 percent higher than with whole-body narrowband UVB irradiation, while the rest of the body receives considerably less radiation. The effectiveness of the method has been documented in numerous studies.

In our practice a pulsed XeCl excimer laser at 308 nm is used for this [PLATZHALTER: Gerätemodell bestätigen]. Because the treatment field is small, the method suits individual, small plaques and those regions that whole-body irradiation reaches poorly.

Areas of application

• Psoriasis in circumscribed, small-area plaques
• Stubborn plaques that respond only partly to topical treatment
• Plaques on the scalp and in the armpits, groin and anal region, which whole-body UVB irradiation barely reaches

Procedure

1. Examination and assessment of the plaques

   We first look at the number, size and location of the plaques and go through the treatments you have had so far. That tells us whether targeted irradiation makes sense or whether another form of phototherapy fits better.

2. Targeted irradiation at 308 nm

   The treatment field is small, roughly 4 cm². The light therefore reaches only the affected spots, while the healthy skin is left out. This also makes the scalp, armpits, groin and anal region accessible.

3. Stepwise increase of the dose

   Because the light is delivered so precisely, treatment can begin at a higher dose and increase it more quickly from session to session. The dose is set by the doctor and adjusted to how your skin reacts.

4. Re-treating fresh plaques

   If plaques return after healing, they are usually small at first. Treated early, a few irradiation cycles are as a rule enough.

What to expect

• For psoriasis, 10 to 15 sessions are as a rule enough for the treated areas to clear largely. For vitiligo (white spot disease) it is usually 30 to 50 cycles.
• Compared with conventional irradiation regimes the skin changes respond faster and fewer irradiation cycles are needed. Accompanying medication, topical and systemic, can often be reduced.
• Once the plaques have cleared, experience shows that the treated areas stay stable for about 6 to 12 months.
• Even stubborn plaques tend to clear well in our experience. A particular result cannot be promised, however.

Risks & notes

• In the irradiated area an inflammation resembling sunburn is not uncommon.
• Like any UV irradiation, the treatment causes a temporary increase in pigment (browning) in the treated area. It recedes on its own once the therapy has ended.
• Psoriasis is genetically determined, that is, constitutional. Even with the excimer laser it cannot be cured; what is treated are the existing plaques.
• Since this is a UV treatment, too high a dose can cause blistering. With cumulatively high UV doses, a slightly increased long-term risk of skin cancer cannot be entirely ruled out, as with any UV therapy. The dose is therefore controlled and limited by the doctor; we discuss your individual risk with you.
• Excimer laser treatment is not yet covered by the German statutory health insurers. It cannot be billed via the insurance card and is invoiced under the official German scale of medical fees (GOÄ) as an IGeL service (individual health service). Private insurers as a rule cover the costs in full.

Further uses of the excimer laser

Irradiation at 308 nm is used not only for psoriasis, but among other things for:

• vitiligo (white spot disease)
• atopic dermatitis
• loss of pigment (hypopigmentation) in scar areas and after laser treatment of acne scars
• patchy hair loss (alopecia areata)
• loss of pigment in stretch marks (striae cutis distensae)
• circumscribed eczema such as lichen simplex chronicus (Vidal), atopic prurigo and eczema of the hands and feet

About the technology

• The excimer laser emits its light entirely at 308 nm. With excimer flash lamps, by contrast, the figure of 308 nm refers to the emission maximum; their light is spread across a broader spectrum.
• The small treatment field of roughly 4 cm² allows targeted treatment of small areas and of body regions that are otherwise hard to reach with UV light.

Frequently asked questions

How many sessions are needed?

For psoriasis, 10 to 15 sessions are as a rule enough for the treated areas to clear largely. For vitiligo (white spot disease) it is usually 30 to 50 cycles.

Does this cure psoriasis?

No. Psoriasis is constitutional and cannot be cured with the excimer laser either. What is treated are the existing plaques; afterwards the skin usually stays stable for about 6 to 12 months. If new plaques appear, treating them early is sensible.

How does this differ from UVB irradiation at 311 nm?

Narrowband UVB irradiation covers the whole body or a large part of it. The excimer laser irradiates only the affected plaques. The light dose within the plaque is therefore higher, while the rest of the body receives considerably less UV radiation.

Does health insurance cover the costs?

The treatment is not yet covered by the German statutory health insurers. It is invoiced under the German scale of medical fees (GOÄ) as an IGeL service. Private insurers as a rule cover the costs in full. We clarify the framework for your case with you beforehand.