title: Double-blind, randomised, placebo controlled low level laser therapy study in patients with primary Raynaud's phenomenon.
abstract: BACKGROUND
  No causal treatment of primary Raynaud's phenomenon is available due to its unclear aetiology. Low level laser therapy (LLLT) is applied in a multitude of medical conditions often without sufficient evidence of efficacy and established mechanisms. To asses the effect of this therapy in patients with primary Raynaud's phenomenon a randomised, double blind, placebo controlled cross over study was designed.
  
  
  METHODS
  Absolute and relative frequency and intensity of vasospastic attacks during three weeks of either LLLT or placebo therapy and results of infrared thermography before onset and at the end of both therapy sequences were evaluated in 15 patients with primary Raynaud's phenomenon.
  
  
  RESULTS
  Frequency of Raynaud's attacks was not significantly affected by low level laser therapy. Compared to placebo a significantly lower intensity of attacks during laser irradiation was observed, but no transfer effect occurred. Additionally the mean temperature gradient after cold exposure was reduced after laser irradiation, while the number of fingers showing prolonged rewarming was unaffected.
  
  
  CONCLUSIONS
  Though further studies are necessary to confirm these results we could demonstrate for the first time in a double blind placebo controlled clinical trial that low laser therapy is a potential candidate for an effective therapy of Raynaud's phenomenon, although effects seem to be of short duration.
authors.affiliation: Angiologische Ambulanz und Tagesklinik, Hanuschkrankenhaus Wien. mirko.hirschl@wgkk.sozvers.at
authors.forename: M
authors.initials: M
authors.lastname: Hirschl
authors.forename: R
authors.initials: R
authors.lastname: Katzenschlager
authors.forename: K
authors.initials: K
authors.lastname: Ammer
authors.forename: P
authors.initials: P
authors.lastname: Melnizky
authors.forename: O
authors.initials: O
authors.lastname: Rathkolb
authors.forename: M
authors.initials: M
authors.lastname: Kundi
mesh_terms: D000328:Adult; D000368:Aged; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D028022:Low-Level Light Therapy; D008297:Male; D008875:Middle Aged; D011928:Raynaud Disease / Q000628:therapy*; D016896:Treatment Outcome