In recent years great interest in phototherapy as an effective method for treatment of skin diseases has been
observed. The biological effect of UV depends on the dose and the wavelength as well as patients’ sensitivity
to UV. Recently particular interest is more focused on narrow-band UVB (311-313 nm), which is considered safe
and effective treatment for a variety of skin diseases. In the article the immunomodulatory and
immunosuppressive mechanism of UVB 311 nm is described. The benefits and complications typical for this
method are presented