8. Phototherapy
Light exposure and vitamin D can both help to improve the clear-up of psoriasis and reduce the likelihood of flare ups. Thus, it should come as no real surprise that phototherapy can also be useful. Here, light is used against the skin with specific lightwaves that mimic that of the sun.
The best wavelengths are 311-313 nanometers. Special lamps have been developed for this purpose (UVB lamps) and these should include a timer to prevent burning or over-exposing the skin.
Of course there are potential risks involved when using UV rays, so you should speak with your doctor and not attempt to self-medicate in this instance.