Pilot study of the effect of ultraviolet light on pain and mood in fibromyalgia syndrome.

Background: There is a lack of effective systemic or adequate symptomatic treatment for pain associated with fibromyalgia syndrome (FMS). Anecdotes suggest ultraviolet (UV) light may be of some benefit.
Purpose: The purpose of the present study was to determine if UV is effective in ameliorating chronic pain in persons with FMS.
Methods: Nineteen subjects with FMS were enrolled in a controlled trial of UV and non-UV (control) tanning beds for 2 weeks, followed by randomization to receive UV or non-UV (control) exposure for 6 additional weeks. A follow-up interview was conducted 4 weeks after the last treatment. Pain was assessed with an 11-point numerical pain rating (Likert scale), a visual analogue pain scale (VAS), and the McGill Pain Questionnaire. Mood variables were also assessed.
Results: During the initial 2 weeks when subjects received both UV and non-UV (control) exposures, the 11-point Likert scale pain score decreased 0.44 points after exposure to UV from pre-exposure levels (S.E. = .095). Additionally, UV exposure resulted in greater positive affect, well-being, relaxation, and reduced pain levels when compared to non-UV (control) exposure (Odds Ratio [OR] = 2.80, p = 0.0059). Following the randomized treatment period, there was slight improvement in pain as measured by the McGill Pain Questionnaire in the UV group compared to the non-UV (control) group (12.2 versus 14.1; p = 0.049); the other pain scales yielded nonsignificant results. Assessment 4 weeks after the last treatment showed no significant differences in scores in the adjusted means for outcomes.
Conclusions: Results from this pilot study suggest that tanning beds may have some potential in reducing pain in persons with FMS.