Nowadays the preferred method for radiotherapy treatment of skin diseases like psoriasis is through the use of the ‘B’ bandwidth of the UV spectrum, since this requires no photo-sensitizing agent. But some patients do not respond to UVB treatment, hence a UV lamp with an ‘A’ bandwidth of the UV spectrum is used, and here Philips offers a choice of either a fluorescent lamp or the more compact PLS/PLL lamps. Both are ideal for when the ‘B’ bandwidth of the UV spectrum is ineffective. These PUVA lamps have a wavelength of 315 to 380 nm and are not only used for the treatment of psoriasis but are also commonly used for more than 20 other diseases. Besides the PUVA lamps, we also offer UVA-1 lamps with a radiation wavelength between 350 and 400 nm. N.B.: Our UVB lamps are NOT registered with FDA as medical devices as they are NOT packaged or labeled for commercial distribution for health-related purposes. US customers are referred to the UVB and UVA lamp range brochure US version.