Association of occupational exposure with features of systemic sclerosis

Abstract

Background: Occupational exposure is reported as playing a substantial causative role in systemic sclerosis (SSc).

Objective: We sought to compare the characteristics of SSc in patients with and without occupational exposure to crystalline silica/solvents.

Methods: In all, 142 patients with SSc were enrolled in this prospective study. An expert committee performed blind evaluation of occupational exposure to crystalline silica/solvents.

Results: Patients exposed to crystalline silica more often exhibited: diffuse cutaneous SSc (P = .02), digital ulcers (P = .05), interstitial lung disease (P = .0004), myocardial dysfunction (P = .006), and cancer (P = .06). Patients exposed to solvents more frequently developed: diffuse cutaneous SSc (P = .001), digital ulcers (P = .01), interstitial lung disease (P = .02), myocardial dysfunction (P = .04), and cancer (P = .003); in addition, these patients were more frequently anti-Scl 70 positive and anticentromere negative. Under multivariate analysis, significant factors for SSc associated with exposure to silica/solvents were: male gender (odds ratio 19.31, 95% confidence interval 15.34-69.86), cancer (odds ratio 5.97, 95% confidence interval 1.55-23.01), and digital ulcers (odds ratio 2.42, 95% confidence interval 1.05-5.56).

Limitations: The cohort originated from a single geographic region.

Conclusion: Occupational exposure to crystalline silica/solvents is correlated with more severe forms of SSc characterized by: diffuse cutaneous involvement, interstitial lung disease, general microangiopathy (digital ulcers and myocardial dysfunction), and association with cancer. Occupational exposure should be systematically checked in all patients with SSc, as exposed patients seem to develop more severe forms of SSc.

Keywords: cancer; crystalline silica; digital ulcers; interstitial lung disease; occupational factors; solvents; systemic sclerosis.