An overview of environmental risk factors in systemic sclerosis.

Systemic sclerosis (SSc) is a connective tissue disease with a complex and multifactorial pathogenesis, characterized by excessive collagen deposition and vasculopathy, leading to skin fibrosis and involvement of internal organs. Regarding the aetiology of SSc, our current knowledge is still limited; however, as for other autoimmune syndromes, the disease is probably caused by both endogenous and exogenous factors. Among the exogenous factors, in the past decades, several environmental exposures, including occupational exposure to pollutants, chemicals and hand-arm vibrations as well as infections, silicone and use of drugs, have been suggested to play a role in the development of SSc. The following review analyzes the most recent literature to examine the relationship between environmental exposures and SSc.