Environmental risk factors in systemic sclerosis.

PURPOSE OF REVIEW: Environmental risk factors have been implicated in the pathogenesis of systemic sclerosis (SSc). Recent evidence further supports this relationship and constitutes the focus of this review article.

RECENT FINDINGS: Exposure to silica through various occupations remains one of the main environmental risk factors for SSc. Emerging evidence has also implicated organic solvents in the development of this difficult-to-manage condition. The individual role of these toxins is, however, difficult to ascertain due to methodological limitations in study design. Other occupational agents, such as epoxy resins, welding fumes and hand-arm vibration, have been investigated, but no definitive associations may be made due to small sample sizes. The controversial association between silicone breast surgery and SSc has not been proven and, amongst other non-occupational factors, smoking does not increase the risk of development but does appear to impact upon the severity of disease.

SUMMARY: A number of environmental exposures are likely to play an important role in the development of the disease; however, current evidence consists mainly of heterogeneous studies with relatively small sample sizes. In the future, multicentre collaborations may help inform preventive strategies.