Systemic sclerosis due to crystalline silica exposure among jewelry workers in Korea: two case reports

Systemic Sclerosis in Males-Deciphering the Enigma of Erasmus Syndrome

Background

Systemic sclerosis is an autoimmune connective tissue disease characterized by fibrosis in skin and internal organs. Chronic exposure to silica may not only lead to silicosis of lungs but also systemic sclerosis. Systemic sclerosis is relatively commoner in females; however, occupational exposure to silica in males makes them vulnerable to silica--associated systemic sclerosis (Erasmus syndrome).

Objective

To describe the clinico-epidemiological aspects of systemic sclerosis in males in a retrospective cohort study.

Materials and Methods

The data were analysed retrospectively for demographic profile and clinical characteristics including examination findings, laboratory investigations, and treatments of all male patients diagnosed with systemic sclerosis with or without silica exposure, managed from January 2018 to December 2021.

Results

Eight out of twelve patients were having silica exposure in the form of stone cutting, cement exposure, and working with concrete. The average age was 55 ± 10.72 years with average smoking exposure of around 24.4 ± 12.8 pack years. Skin thickening was reported by all patients with an average modified Rodnan score of 18.33/51 in diffuse and 7/51 in limited cutaneous systemic sclerosis. Raynaud's phenomenon and sclerodactyly were universal findings, while 9 (75%) patients had digital pitted scars. Antinuclear antibodies were present in all patients and specific antibodies substantiated the clinical assessment in almost all patients. Interstitial lung disease was the most common systemic finding present in 11 (91%) patients and tuberculosis was diagnosed in 2 (25%) cases with silica exposure. Gastrointestinal and cardiac system involvement was seen in 5 (41.6%) and 4 (33.3%) patients, respectively.

Conclusion

Systemic sclerosis in males against the gender predilection indicates the role of occupational exposure. Silicosis and systemic sclerosis synergistically add to lung damage, and at the same time, these patients are more prone to infections like tuberculosis.

Creazione di una banca dati delle concentrazioni occupazionali e ambientali di silice libera cristallina ai fini della valutazione delle esposizioni pregresse e attuali

BACKGROUND

Professional exposure to respirable dust containing crystalline silica is of great interest for the serious lung diseases resulting from exposure.

METHODS

During the period 1986-2019, 3611 exposure data to crystalline silica were collected from companies in central Italy. The data were divided and statistically analyzed based on the sampling system (Cyclone Dorr Oliver, CIP 10-R, Cyclone GS3, SKC plastic selector, Cyclone Higgins-Dewell and Cyclone Lippmann) and the ATECO code (code of economic activity, Italian acronym, used to classify companies when they interface with public institutions) of the companies in which they were collected. For each ATECO code, the division was made according to the type of sampling (personal or static) and the descriptive statistics of the data were calculated.

RESULTS

Overall, for personal samples, 8.8% of the data exceeds 0.1 mg/m3, 19.6% exceeds 0.05 mg/m3 and 33.8% exceeds 0.025 mg/m3, the limit values set by the EU Directive 2019/130, suggested by the SCOEL and published by ACGIH respectively. The ATECO codes with the highest worker exposure (geometric means 0.067 and 0.069 mg/m3) were 23.31.00 (manufacture of ceramic tiles for floors and walls) and 23.42.00 (manufacture of ceramic sanitary ware), while the lowest exposure is found in 81.29.91 (cleaning and washing of public areas, removal of snow and ice including shedding of sand) with a geometric mean of 0.002 mg/m3.

DISCUSSION

Despite the general reduction over time, there are still many sectors in which data are higher than the current occupational exposure limits; especially in these sectors it is necessary to implement the measures to fully assess worker exposure.

A Pathological Study of Acute Pulmonary Toxicity Induced by Inhaled Kanto Loam Powder

The frequency and volume of Asian sand dust (ASD) (Kosa) are increasing in Japan, and it has been reported that ASD may cause adverse respiratory effects. The pulmonary toxicity of ASD has been previously analyzed in mice exposed to ASD particles by intratracheal instillation. To study the pulmonary toxicity induced by inhalation of ASD, ICR mice were exposed by inhalation to 50 or 200 mg/m³ Kanto loam powder, which resembles ASD in elemental composition and particle size, for 6 h a day over 1, 3, 6, 9, or 15 consecutive days. Histological examination revealed that Kanto loam powder induced acute inflammation in the whole lung at all the time points examined. The lesions were characterized by infiltration of neutrophils and macrophages. The intensity of the inflammatory changes in the lung and number of neutrophils in both histological lesions and bronchoalveolar lavage fluid (BALF) appeared to increase over time. Immunohistochemical staining showed interleukin (IL)-6- and tumor necrosis factor (TNF)-α-positive macrophages and a decrease in laminin positivity in the inflammatory lesions of the lung tissues. Electron microscopy revealed vacuolar degeneration in the alveolar epithelial cells close to the Kanto loam particles. The nitric oxide level in the BALF increased over time. These results suggest that inhaled Kanto loam powder may induce diffuse and acute pulmonary inflammation, which is associated with increased expression of inflammatory cytokines and oxidative stress.