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.