Tanning beds are not safe for people with lupus. The bulbs in tanning beds produce ultraviolet light rays. It is the ultraviolet light rays that cause the skin to tan. The majority of people with lupus tend to be unusually sensitive to ultraviolet light. That is to say, exposure to excessive ultraviolet light, especially the UVB sunburning rays, can cause lupus skin lesions to appear, or make existing lupus skin lesions worse. Ultraviolet light can also activate the internal, or systemic, manifestations of lupus in some people. 

There have been many examples of people with lupus skin disease who were thought to have psoriasis instead, and were then treated for psoriasis in medical phototherapy cabinets that are similar to tanning beds. A number of these people almost died from severe activation of their lupus following such mistaken treatment.  Some research suggests that low doses of very long ultraviolet light wavelengths, in what is called the ""UVA-1"" range, can improve certain forms of lupus skin disease and mild forms of systemic lupus.  However, high doses of UVA have been shown to induce skin lesions in some individuals.

Therefore, the biological effects that people with lupus might experience (i.e. getting worse or better) are likely to be critically dependent upon the amount of the different wavelengths of ultraviolet light energy that their skin receives.  In a routine commercial tanning bed setting, it would be quite difficult for people with lupus to know how much of the various UV wavelengths they are receiving. Thus, for people with lupus, visiting a tanning salon may be too risky.