Silica systemic sclerosis

Englert H. et al., Male systemic sclerosis and occupational silica exposure-a population-based study, Aust. N. Z. J. Med., 30, 215, 2000. 

A fairly strong and consistent association between exposure, primarily in occupational settings, to solvents (e.g. trichloroethylene) and scleroderma has been reported in numerous epidemiological studies (see chapter 8). Scleroderma-like diseases can also be induced by other chemical compounds, such as drugs (D Cruz, 2000) and silica ( Erasmus syndrome ). Workers exposed to vinyl chloride monomers exhibit clinical features that resemble systemic sclerosis, such as fibrotic skin lesions, pulmonary fibrosis, and skin capillary abnormalities. However, vinyl chloride disease also harbours several features that are clearly distinct from systemic sclerosis. After exposure is discontinued, skin lesions, capillary abnormalities, and acroosteolytic lesions revert to nearly normal (Haustein Ziegler, 1985). 

Cowie RL (1987) Silica-dust-exposed mine workers with scleroderma (systemic sclerosis). Chest, 92 260-262... 

Sluis-Cremer GK, Hessel PA, Hnizdo EH, Churchill AR, Zeiss EA (1985) Silica, silicosis, and progressive systemic sclerosis. Br J Ind Med, 42 838-843. 

Orthop Clin North Am 14 675-697 Riidlinger R, Bunney MH, Grab R, et al. (1984) Warts in fish handlers. Br J Dermatol 120 375-381 Rustin MHA, Bull HA, Ziegler V, et al. (1989) Silica exposure and silica-associated systemic sclerosis. Br J Dermatol I2i[suppl 341 29-30... 

Table 2. Occupations of our systemic sclerosis patients with verified silica-dust exposure (n = 111)...

In conclusion, silica may induce systemic diseases with various clinical and serological manifestations systemic sclerosis with ACA, ATA or anti-nucleolar antibodies, systemic LE and systemic LE-like diseases with anti-dsDNA and/or anti-RO/SS-A and anti-car-diolipin antibodies, and necrotizing systemic vasculitis... 

Table 5. Published cases of systemic sclerosis (SSc) in association with silica exposure and silicosis, respectively ...

Fig. 1. Silica can activate various cell types involved in the pathophysiology of systemic sclerosis (SSc). Macrophages activated by silica in vitro liberate the same cytokines and growth factors known to be active in the pathophysiology of idiopathic SSc. Microvascular endothelium is involved in silica-induced as well as idiopathic SSc with similar activation patterns in vitro and in vivo. Dermal fibroblasts are affected by silica in vitro, and fibroblasts are the cells producing large amounts of extracellular matrix in vivo. In vitro, the synthesizing capacity of fibroblasts depends greatly on culture conditions. All these effects are based on our in vitro experiments with silica shown in italic. These effects are similar to pathophysiological events known from idiopathic SSc...

Oghiso Y, Kubota Y (1986) Enhanced interleukin 1 production by alveolar macrophages and increase in la-positive lung cells in silica-exposed rats. Microbiol Immunol 30 1189-1198 Ostlere LS, Harris D, Buckley C, Black C, Rustin MH (1992) Atypical systemic sclerosis following exposure to vinyl chloride monomer. A case report and review of the cutaneous aspects of vinyl chloride disease. Clin Exp Dermatol 17 208-210... 

Yanez-Diaz S, Moran M, Unamuno P, Armijo M (1992) Silica and trichloroethylene-induced progressive systemic sclerosis. Dermatology 184 98-102... 

Rustin MHA, Ziegler V, Mehlhorn L, et al. (1990) Silica associated systemic sclerosis is clinically, serologically and immunologically indistinguishable from idiopathic systemic sclerosis. Br J Dermatol 123.725-734... 

The strength of the association between silicosis and connective tissue disease varies with the type of connective tissue disorder. The risk of developing systemic sclerosis, particularly in workers with high exposure to silica dust, is well established, although such casual associations between silicosis, rheumatoid arthritis and systemic lupus erythematosis are less widely reported (Rosenman 1999 Sluis-Cremer et al. 1985, 1986 Sanchez-Roman et al. 1993)... 

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