title: Infections are not increased in scleroderma compared to non-inflammatory musculoskeletal disorders prior to disease onset.
abstract: The etiology of scleroderma (SSc) is unknown; immunogenic stimuli such as infections and vaccinations could theoretically be risk factors for scleroderma. Our objective was to assess the relationship between viral and bacterial infections, and vaccinations, prior to diagnosis of SSc compared to non-inflammatory controls.
  
  
  METHODS
  A questionnaire was sent to individuals with SSc (n =83) and controls (n=351) with non-inflammatory musculoskeletal (MSK) disorders (osteoarthritis, n = 204; tendonitis, n = 58; fibromyalgia, n= 89) from a rheumatology practice. Questions ascertained past infections, exposure to infectious agents and vaccination history.
  
  
  RESULTS
  The response rate was 78% (SSc) and 56% (MSK controls). The mean age was 56 +/- 1.6 (SSc) and 58 +/- 0.9 (MSK); 88% (SSc) and 82% (MSK) were female. No association between prior infections and SSc was observed. In fact, controls were more likely than SSc subjects to report any infection within 1-year prior to disease diagnosis (35% vs. 16%, p<0.006), or to have suffered a trauma to affected joints prior to diagnosis (44% vs. 19%, p<0.0002). Within the 1-year prior to disease diagnosis, controls reported slightly more streptococcal infections (p<0.2), infections with diarrhea and vomiting (p<0.3), and antibiotic use (p<0.09), although none of these results were statistically significant. Histories of any hepatitis, rubella, any bacterial infection, and having had a previous positive tuberculosis skin test were not significantly different between groups and were actually more often reported by the control subjects. SSc reported slightly more hepatitis B (p<0.08), more rheumatic fever (p<0.8) in past, and herpes zoster (p<0.4), although no differences reached significance.
  
  
  CONCLUSIONS
  This study does not support that self-report of symptomatic infections are more likely to occur ever (prior to diagnosis) or within 1-year prior to symptom onset of SSc, or that vaccinations in adulthood trigger SSc.
authors.affiliation: Division of Rheumatology, Department of Medicine, The University of Western Ontario, London, Canada. janet.pope@sjhc.london.on.ca
authors.forename: Janet E
authors.initials: JE
authors.lastname: Pope
authors.forename: Jodi L
authors.initials: JL
authors.lastname: Goodwin
authors.forename: Janine M
authors.initials: JM
authors.lastname: Ouimet
authors.forename: Adriana
authors.initials: A
authors.lastname: Krizova
authors.forename: Matthew
authors.initials: M
authors.lastname: Laskin