Digital ultraviolet therapy: a novel therapeutic approach for the targeted treatment of psoriasis vulgaris.

BACKGROUND: 8-Methoxypsoralen-UVA (PUVA) and narrowband ultraviolet B (NB-UVB) are well-established treatments for chronic plaque-type psoriasis vulgaris. However, long-term risks of PUVA therapy include premature skin ageing and squamous cell carcinoma.

OBJECTIVES: To develop a device for targeted UV therapy of psoriatic plaques with protection of the healthy adjacent skin to reduce the risk for premature skin ageing and squamous cell carcinoma.

METHODS: In total 28 patients with exacerbated psoriasis vulgaris were treated with the digital phototherapy device skintrek(®) [cream PUVA (n = 8), bath PUVA (n = 11) and UVB (n = 9)] or with conventional bath PUVA (n = 9) or NB-UVB (n = 4).

RESULTS: The local Psoriasis Area and Severity Index (PASI) score was significantly reduced from a mean of 6·25 at baseline to 2·75 at the end of therapy in the skintrek cream PUVA group, from 6·4 to 3·0 in the skintrek bath PUVA group and from 5·5 to 2·0 in the skintrek UVB group. Treatment with skintrek cream PUVA reduced the mean local PASI by 54%, while skintrek bath PUVA did so by 51% and skintrek UVB by 63%. Targeted skintrek PUVA and skintrek UVB of inflamed psoriatic skin avoided skin pigmentation and were not inferior to conventional bath PUVA and NB-UVB therapy regimens.

CONCLUSIONS: Targeted UV therapy of psoriatic plaques with the digital phototherapy device skintrek is as effective as conventional cream and bath PUVA, as well as NB-UVB, while simultaneously sparing the healthy adjacent skin. It therefore potentially reduces the carcinogenic risk, reduces premature skin ageing and avoids tanning of healthy surrounding skin.