Targeted 307 nm UVB‐excimer light vs. topical dithranol in psoriasis

Abstract

EditorPhoto(chemo)therapy is a well established psoriasis therapy. As demonstrated by Parrish and Jaenicke, the action spectrum for psoriasis clearing is 300-313 nm. 1 In recent years, targeted UVB phototherapy with 308 nm-excimer laser and excimer light has been developed. It avoids unnecessary UV-exposure of non-lesional skin and allows higher dosages for lesional skin what results in a more rapid clearing. Both seem to achieve comparable efficacy with lower investment costs for excimer light. [2][3][4][5] We report a pilot trial in moderate plaque-type adult psoriasis patients using a newly developed 307 nm-excimer lamp compared to topical dithranol.This is an open clinical pilot trial with permission from the local ethical committee. Every patient served as his ⁄ her own control. Systemic therapy was not allowed. Two target lesions of comparable size and plaque-modified Psoriasis Activity and Severity Index (PSI) scores 6 were selected for monitoring. Lesion A was treated with 307 nm-excimer light only. Lesion B was treated with dithranol.Targeted UVB treatment was performed with a new device three times starting with the minimal erythema dose (MED). The mean 307 nm-excimer light exposure per session was 20 s resulting in a mean total irradiation time of 37 s. With the support of a quartz bar targeted treatment with a focus area of 3 cm 2 is realized. The average UVB med irradiance was 18 mW ⁄ cm 2 , maximum 20 mW ⁄ cm 2 . The average total energy applied was 2.05 J, with 1.13 J in the UVB med range. We used the fluorescence-remission imaging (FRIS) as described before 7 for non-invasive objective measurements.A total of 21 patients were recruited with 19 patients completing the investigation [15 men, six women]. The mean age was 51 years (range 26-84 years). All patients had a Fitzpatrick skin phototype II or III. The mean improvement of the PSI score was 3.0 for lesion A (three times excimer light) and for lesion B (twice daily dithranol) (P = 0.965; Mann-Whitney U-test). The results clearly demonstrate an equipotency of the targeted phototherapy to topical dithranol (Table 1).Tolerance was superior with targeted phototherapy. The most common adverse effect in excimer light-treated lesions was a mild to moderate erythema (n = 11), temporary blistering (n = 3), but there was no scarring or oozing. The NADH-fluorescence is reduced in psoriatic lesions. Excimer light treatment results in a normalization of NADH-fluorescence in contrast to dithranol.The UVB-excimer lamps are an alternative for targeted UVBtherapy in psoriasis. They seem to be as effective as non-targeted narrow-band UVB and 308 nm-excimer laser therapy. 4,5 There has been no study comparing targeted UVB phototherapy with topical treatments. In this study for the first time 307 nm-excimer light therapy was compared to topical dithranol therapy. Dithranol is one of the most potent topical antipsoriatic drugs. 8 We used a newly developed 307 nm-excimer light for targeted UVB-therapy and compared its efficacy and safety to topical dithranol twice d...

Pustular Palmoplantar Psoriasis Successfully Treated with Nb-UVB Monochromatic Excimer Light: A Case-Report

“…However, during the last years focused phototherapy with narrowband UVB (307-311 nm) showed a similar efficacy, but without a risk of secondary skin cancer development [ 21 - 24 ]. This therapeutical approach considers that psoriasis patients undergoing phototherapy usually receive high cumulative doses of radiation during their lives, thus leading to secondary cutaneous disorders, like photoaging, teleangectasias, excessive tanning, etc.…”

S2k guideline: Laser therapy of the skin

“…Regarding laser treatment of psoriasis vulgaris, there are reports on the use of dye lasers [14], also in cases of nail involvement [15][16][17][18]. Excimer lasers [19][20][21] alone or combined with typical antipsoriatic drugs [22] are frequently mentioned in the medical literature. Please consult the pertinent guideline [23] for general information.…”

S2k‐Leitlinie: Lasertherapie der Haut

“…Für die Lasertherapie der Psoriasis vulgaris finden sich Hinweise auf den Einsatz von Farbstofflasern [14], auch bei Nagelbeteiligung [15][16][17][18]. Excimer-Laser [19][20][21] allein oder in Kombination mit typischen Antipsoriatika [22] werden in der Literatur häufig erwähnt. Im Allgemeinen sei auf den Appendix der entsprechenden Einzelleitlinie [23] verwiesen.…”