Action Spectrum for Phototherapy of Psoriasis

Abstract

Using a monochromator the action spectrum for ultraviolet phototherapy of psoriasis was determined for radiation between 254 and 313 nm and compared to the action spectrum for erythema of uninvolved adjacent skin. Daily exposures of different doses of 254, 280, 290, 296, 300, 304 and 313 nm radiation were observed. Wavelengths of 254, 280, 290 nm were erythemogenic but not therapeutic even at 10 to 50 times the minimal erythema dose. At the other wavelengths studied, the 2 action spectra were similar. In general, fixed daily doses cleared at lower cumulative dose than did incrementally increased daily doses. The small number of suberythemogenic exposure doses required suggests that monochromatic radiation may have advantages over broadband sources.

Phototherapy of mycosis fungoides

“…A technical innovation that specifically changed phototherapy was the development of the TL-01 fluorescent lamp (64). This lamp emits within a narrow spectrum of around 311 nm and thus according to the available action spectra should be ideally suitable for the clearance of psoriatic lesions with a minimized erythema risk (65). Accordingly, narrowband UVB (NB-UVB) has been shown to be better than broadband UVB and similarly effective as PUVA in the treatment of psoriasis (66).…”

Targeted phototherapy of plaque-type psoriasis using ultraviolet B-light-emitting diodes

“…Action spectrum studies have established that wavelengths between 304 and 313 nm are the most effective to clear psoriatic lesions, while wavelengths from 290 to 300 nm produce sunburn reaction, but have no therapeutic effect. 1 These findings led to the introduction of narrowband UVB sources (peak emission at 311 ± 2 nm), which have been successfully used to treat psoriasis for more than 20 years. The efficacy of UVB phototherapy has been demonstrated in several studies and therefore is recommended for the treatment of psoriasis in the guidelines of dermatological societies all over the world.…”

Current Approach to Phototherapy Applications in Dermatology Practice: Part 1. History, Lamps, Ultraviolet Radiation Levels Measurement and Phototherapy Modalities

“…Dar bant UVB'nin bir fototerapi yöntemi olarak ortaya çıkışı, Parrish ve Jaenicke tarafından psoriasisteki etki spektrumunun 313 nm'de pik yaptığının keşfedilmesini izleyerek gerçekleşmiştir (8). Bu keşif, psoriasiste, 296 nm'den kısa dalgaboyuna sahip ışınların eritemojenik olduklarını ancak terapötik olmadıklarını göstermiş, daha uzun dalga boyuna sahip ışınlarla monokromatik irradyasyon yapıldığında, psoriatik plakların suberitemojenik dozlarda daha kısa sürede iyileştikleri bilgisini ortaya çıkarmıştır.…”