About phototherapy Phototherapy is the use of non-ionizing electromagnetic energy, typically ultraviolet wavelengths, for therapeutic effect. Commonly used wavelengths are  broad band UVB (BB-UVB), narrow band UVB (nbUVB) and UVA. nbUVB is considered the safest and most effective wavelength for treatment of  psoriasis.  UVA is used primarily for photochemotherapy (PUVA), while UVA1 may be useful for atopic… Read More