What is the difference between UVA, Narrow Band UVB, and Broad Band UVB?

Broadband UVB, highly effective in the treatment of psoriasis, has been used for years, often times in combination with skin preparations such as crude coal tar. UVB is about 1000 times more likely to cause sunburn than UVA and UVB is the reason that you must be careful on those hot summer days.

Narrow-band UVB is relatively new. Its ultraviolet output is concentrated in a very narrow range that many scientists believe is the most effective range for treating many skin diseases. While a number of studies have been done using Narrow Band for the treatment of psoriasis, it also shows promise as an effective modality for many other skin diseases as well such as Vitiligo and possible Eczema.