Should systemic sclerosis be recognised as an occupational disease in Switzerland?

Abstract

Systemic sclerosis is a rare autoimmune disease characterised by a multifactorial aetiology involving a gene-environment interaction. Despite the growing epidemiological arguments for odds ratio (OR) data showing an association with occupational exposure, systemic sclerosis is not currently included in the list of recognised occupational diseases in Switzerland, unlike other northern European countries. Future recognition will be conditional on the demonstration of a strong association between the disease and occupational exposure in the scientific literature. The present article's main goal is to present five cases of systemic sclerosis investigated for possible occupational aetiologies during occupational pathology consultations at the Institute for Work and Health, in Lausanne. The occupational aetiologies of these cases are discussed against the background of a literature review of publications from the past 20 years in order to determine whether recognition as an occupational disease is possible within Switzerland's legal framework. Epidemiological studies of systemic sclerosis have identified strong associations with occupational factors such as exposure to silica and solvents, with ORs >2, and weaker associations with epoxy resins and welding fumes. Other occupational exposures are also known to induce systemic sclerosis-like diseases, such as vinyl chloride disease and toxic oil syndrome. All five patients had been exposed to either silica, solvents, or both. Given their exposure and the data in the literature, four patients had their cases declared to their accident insurance companies and two of them were recognised as suffering from an occupational disease by the Swiss National Accident Insurance Fund. Our literature review enabled us to design a short questionnaire to help general practitioners and rheumatologists to identify those patients with systemic sclerosis who are likely to have their illness recognised as an occupational disease.

A broad look into the future of systemic sclerosis

“…Pesticides increased the risk of SSc in females by an OR > 3 in contrast to males, who did not show an increased risk. 2…”

“…1 Epidemiological studies of SSc identified strong associations with occupational factors such as exposure to silica and solvents with odds ratios (ORs) > 2 and weaker associations with epoxy resins and welding fumes. 2 Interestingly, sex is an influencing factor to be considered in the increase of risk for SSc. For example, exposure to silica increased the risk of SSc by an OR > 3 in males, while it was lower in females.…”

“…Pesticides increased the risk of SSc in females by an OR > 3 in contrast to males, who did not show an increased risk. 2 Another interesting area that alters the immune response and thus influences the pathophysiology of SSc is the microbiome. As indicated recently, faecal transplantation changing the gut microbiome can improve at least some GI symptoms.…”

Etiological factors of systemic sclerosis in the southeast region of Romania

“…The most common occupational exposure is to silica dust, which induces silicosis, rheumatoid arthritis and lung cancer; the association of silicosis with SSc or mixed connective tissue disease, known under the name of Erasmus syndrome, has also been considered for inclusion in the occupational diseases category. Researchers suggest that SSc associated with silica dust exposure should be included in the occupational diseases category, even when silicosis is not present (17,18). Silicon dioxide nanoparticles (nano-SiO 2 ) in their amorphous state are microparticles with a diameter of less than 100 nm and a very low density, which can easily become airborne and inhaled.…”

“…Zhao et al also revealed the significant exposure to ketones (18). Recent studies show that epoxy resins, which are included in the list of occupational toxins, may be involved in the onset of SSc (17,18,20). Not only occupational exposure to toxins poses a risk, but also constant or accidental pollution through water and air contamination with halogenated compounds and aromatic hydrocarbons, such as benzene, xylene and toluene (21).…”