Silica-associated limited systemic sclerosis after occupational exposure to calcined diatomaceous earth.

Silica-associated systemic sclerosis can occur in persons using calcined diatomaceous earth for filtration purpose. A limited systemic sclerosis was diagnosed in a 52-year-old male winegrower who had a combination of Raynaud's phenomenon, oesophageal dysfunction, sclerodactyly and telangectasia. The anti-centromere antibodies titre was 1/5000. The patient was frequently exposed to high atmospheric concentrations of calcined diatomaceous earth when performing the filtration of wines. Calcined diatomaceous earth is almost pure crystalline silica under the cristobalite form. The diagnosis of silica-associated limited systemic sclerosis after exposure to calcined diatomaceous earth was made. The patient's disease met the medical, administrative and occupational criteria given in the occupational diseases list 22 bis of the agriculture Social Security scheme and thence was presumed to be occupational in origin, without need to be proved. The diagnosis of occupational disease had been recognized by the compensation system of the agricultural health insurance.