title: Prospective study to evaluate the association between systemic sclerosis and occupational exposure and review of the literature.
abstract: BACKGROUND
  Systemic sclerosis (SSc) has complex pathogenesis and likely multifactorial causes. Environmental exposures have been suggested to play a role in SSc pathogenesis, including occupational exposure to pollutants and chemicals as well as use of drugs leading to modulation of immune response. Thus, this case-control study aimed to assess: the relationship between SSc and occupational exposure; and the risk of SSc related to occupational exposure in male and female patients.
  
  
  METHODS
  From 2005 to 2008, 100 patients with a definite diagnosis of SSc were included in the study; 3 age, gender, and smoking habits matched controls were selected for each patient. A committee of experts evaluated blindly occupational exposure to crystalline silica, white spirit, organic solvents, ketones, welding fumes, epoxy resins, and pesticides; an occupational exposure score was calculated for all subjects. Our findings were compared with previous data in the literature.
  
  
  RESULTS
  Increased ORs for SSc were found for: crystalline silica (p<0.0001), white spirit (p<0.0001), aromatic solvents (p=0.0002), chlorinated solvents (p=0.014), trichlorethylene (p=0.044), ketones (p=0.002) and welding fumes (p=0.021). Elevated risk associated with high final cumulative score in SSc was observed for: crystalline silica, white spirit, chlorinated solvents, trichlorethylene, aromatic solvents, any type of solvents, ketones and welding fumes. A marked association between SSc and occupational exposure was further found for: 1) crystalline silica, chlorinated solvents, trichloroethylene, white spirit, ketones and welding fumes in male patients; and 2) white spirit, aromatic solvents, any type of solvent and ketones in female patients. Finally, we did not find an association between SSc and: 1) the use of drugs that have been speculated to play a role in SSc onset (anorexigens, pentazocine, bromocriptine, l-tryptophan); 2) implants - that are prosthesis, silicone implants, and contact lenses; and 3) dyeing hair. In the literature, SSc has been associated with occupational exposure to silica and solvents, while the association between SSc and specific organic solvents and welding fumes has been anecdotally reported.
  
  
  CONCLUSIONS
  The following occupational factors have an impact in the development of SSc: crystalline silica, white spirit, aromatic solvents, chlorinated solvents, trichlorethylene, ketones and welding fumes. The risk of SSc appears to be markedly associated with high cumulative exposure. Finally, the association between SSc and occupational exposure may be variable according to gender.
authors.affiliation: Department of Internal Medicine, CHU Rouen, Rouen, France; INSERM U 905, University of Rouen IFRMP, Institute for Biochemical Research, Rouen, France. Electronic address: isabelle.marie@chu-rouen.fr.
authors.forename: I
authors.initials: I
authors.lastname: Marie
authors.forename: J-F
authors.initials: JF
authors.lastname: Gehanno
authors.forename: M
authors.initials: M
authors.lastname: Bubenheim
authors.forename: A-B
authors.initials: AB
authors.lastname: Duval-Modeste
authors.forename: P
authors.initials: P
authors.lastname: Joly
authors.forename: S
authors.initials: S
authors.lastname: Dominique
authors.forename: P
authors.initials: P
authors.lastname: Bravard
authors.forename: D
authors.initials: D
authors.lastname: Noël
authors.forename: A-F
authors.initials: AF
authors.lastname: Cailleux
authors.forename: J
authors.initials: J
authors.lastname: Weber
authors.forename: P
authors.initials: P
authors.lastname: Lagoutte
authors.forename: J
authors.initials: J
authors.lastname: Benichou
authors.forename: H
authors.initials: H
authors.lastname: Levesque
mesh_terms: D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure; D011446:Prospective Studies; D012307:Risk Factors; D012595:Scleroderma, Systemic / Q000139:chemically induced*; D012822:Silicon Dioxide / Q000633:toxicity; D012997:Solvents / Q000633:toxicity
chemical_list: D012997:Solvents; D012822:Silicon Dioxide
keywords: Crystalline silica; Ketones; Occupational factors; Solvents; Systemic sclerosis; Welding fumes