Yi et al. Annals of Occupational and Environmental Medicine (2016) 28:24 DOI 10.1186/s40557-016-0106-3 CASE REPORT Open Access Overlap syndrome with Sjögren’s syndrome and systemic sclerosis in a steel rolling mill worker: a case report Min-Kee Yi1, Won-Jun Choi1, Sung-Woo Han1, Seng-Ho Song1, Dong-Hoon Lee1, Sun Young Kyung2 and Sang-Hwan Han1* Abstract Background: There are few reports about work-related factors associated with Sjögren’s syndrome. We report a case of overlap syndrome with Sjögren’s syndrome and systemic sclerosis. Case presentation: A 54-year-old man was admitted due to dyspnea on exertion. The results of physical examination and laboratory findings were compatible with Sjögren’s syndrome with systemic sclerosis. The patient had no pre-existing autoimmune disease, and denied family history of autoimmune disease. The patient worked in the large-scale rolling department of a steel manufacturing company for 25 years. Hot rolling is a rolling process performed at between 1100 °C and 1200 °C, generating a high temperature and a large amount of fumes, involving jet-spraying of water throughout the process to remove the instantaneously generated oxide film and prevent the high generation of fumes. In this process, workers could be exposed to silica produced by thermal oxidation. Other potential toxic substances including nickel and manganese seemed to be less likely associated with the patient’s clinical manifestations. Conclusions: Occupational exposure to silica seemed to be associated with the patient’s clinical manifestations of overlap syndrome with Sjögren’s syndrome and systemic sclerosis. Although the underlying mechanism is still unclear, autoimmune disease including Sjögren’s syndrome affects women more often than men and there was no family history of autoimmune disease. These suggested that there was an association between occupational silica exposure and the disease of the patient. Future research about the association between long-term low dose exposure to silica and the development of autoimmune diseases should be encouraged. Keywords: Overlap syndrome, Sjögren's syndrome, Systemic sclerosis, Silica Background important because it can provide clues to the causes and Connective tissue diseases are systemic autoimmune dis- pathogenic mechanisms of related diseases. Sjögren’s eases characterized by the appearance of a variety of syndrome is an autoimmune exocrinopathy, in which symptoms and organ infiltration [1]. Although widely ac- systemic diseases, such as arthritis, interstitial lung dis- cepted classification standards exist for each disease, ease, and kidney disease, can develop in addition to some undifferentiated connective tissue diseases are dif- characteristic dry eye and mouth symptoms [3]. Sjög- ficult to classify. Overlap syndrome is a condition in ren’s syndrome occurs more frequently in female pa- which the patient develops symptoms corresponding to tients patients than in male patients, especially in two or more classification standards [2]. Although over- middle-aged women. Although the prevalence rate is lap syndrome can cause confusion during diagnosis, it is known to be 0.5–1 %, no accurate reports are present on the prevalence rate in Korea. Sjögren’s syndrome was first described by Johann Mikulicz in 1892 as “Mikulicz’s * Correspondence: [email protected] syndrome” after discovery of the infiltration of small, 1Department of Occupational & Environmental Medicine, Gachon University Gil Medical Center, Incheon, Korea round cells into the salivary glands of a 42-year-old Full list of author information is available at the end of the article © 2016 Yi et al. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Yi et al. Annals of Occupational and Environmental Medicine (2016) 28:24 Page 2 of 8 farmer with bilateral parotid gland enlargement. In 1933, Physical examination findings a Swedish ophthalmologist, Henrik Sjögren, first used On admission, the patient’s vital signs were stable with the term “keratoconjunctivitis sicca” to describe the dry blood pressure of 140/80 mmHg, pulse rate of 86 beats/ eye symptom in 13 patients with accompanying rheuma- min, respiratory rate of 20 breaths/min and body toid arthritis among 19 patients with dry eye and mouth temperature of 37.0 °C. Although the patient showed an symptoms, differentiating it from “xerophthalmia,” the acute ill-looking appearance, his consciousness was clear, dry eye symptom due to vitamin A deficiency [4]. cardiac sound regular, and no heart murmur was heard. Although there have been some reports caused by sil- Fine inspiratory crackles were heard at both lower lung ica, these are considered to be rare [5]. Systemic fields. Finger clubbing was not observed, but fingers sclerosis is a disease characterized by lymphocyte de- were swollen and skin was thickened. The findings in position and fibrosis of various organs, with fibrosis the abdomen, extremities, and neurological examination developing mainly in the skin, kidney, heart, lungs, were normal. and digestive system. Lung infiltration occurs in 70 % of systemic sclerosis patients [6], and although the Radiological findings precise cause of the disease has not been identified, it In a plain chest radiograph obtained on admission, is known that endothelial cells are damaged and fi- ground glass opacities (GGOs) were observed at the broblasts are activated by an autoantibody-mediated lower part of both lungs (Fig. 1). In a chest computed immunological mechanism [7]. Here, we report the tomography image, reticulation and GGOs were ob- case of a steel rolling mill worker with overlapping served in both lungs, leading to the diagnosis of intersti- features of Sjögren’s syndrome and systemic sclerosis. tial lung disease (Fig. 2). Case presentation Laboratory findings Patient information In arterial blood gas analysis performed before Fifty-four year old male hospitalization, pH was 7.4; PaCO2, 38 mmHg; PaO2, 94.2 mmHg; and oxygen saturation, 97.3 %. In a periph- μ Chief complaints eral blood test, the leukocyte count was 8,300/ L; μ The chief complaint of the patient included breathing hemoglobin, 5.2 g/dL; and platelet count, 436,000/ L. In difficulty and coughing during exercise that developed a lung function test, findings of restrictive lung function 2 months previously. disorder were obtained with forced vital capacity (FVC) 2.62 L (67 % of the predicted value), forced expiratory volume in 1 s (FEV1) 2.31 L (80 % of the predicted Current disease history value), the ratio of FEV1/FVC 88 %, forced expiratory Breathing difficulty and coughing aggravated further flow 25–75 % 4.76 L/sec (154 % of the predicted value), during mountain hiking. A pulmonary disease was sus- and peak expiratory flow rate 8.16 L/sec (110 % of the pected from the findings of chest radiographs. The pa- predicted value). tient was hospitalized to obtain an accurate diagnosis and for treatment. Clinical progress The results of bronchoscopy and a lung lavage test re- Past medical history vealed chronic inflammation with fibrosis. The results of On a special health examination performed 5 months lung biopsy were consistent with usual interstitial pneu- before admission, no unusual findings were observed monitis. Breathing difficulty was alleviated with systemic on the plain chest radiography. The patient had no steroid therapy. During admission, the patient com- ophthalmologic diseases, but complained of eye dry- plained of dry mouth and difficulty of swallowing dry ness for several months. He frequently used artificial food without liquid. Immune serologic tests were per- tears because of the eye dryness. formed under suspicion of autoimmune disease. The re- sults of serologic tests were as follows; positive for Personal history antinuclear antibody (1:2560), negative for rheumatoid The patient had a history of smoking 20 cigarettes a factor, positive for anti-SSA (Ro) antibody, negative for day for 20 years and then 10 cigarettes a day for anti-SSB (La) antibody and positive for anti-Scl 70 anti- 10 years; however, he quit smoking 3 months previ- body. The anti-ds DNA level was 7.64 IU/mL (reference ously. He has a history of consuming five bottles level, <7.0 IU/mL). The secretory function of the salivary (350 mL) of soju (approximately 18 % alcohol by vol- gland was considered to be decreased. In a salivary gland ume) per week. No significant family history of auto- scan, the uptake increases in the parotid gland and sub- immune diseases was noted. mandibular gland were relatively normal; however, the Yi et al. Annals of Occupational and Environmental Medicine (2016) 28:24 Page 3 of 8 Fig. 1 A chest radiograph. Ground glass opacities are seen in both lower lung fields ejection fraction of the salivary gland after stimulation the roughing mill and intermediate mill. His major tasks decreased by more than the moderate level. Although were the management of oils, roll exchange of the rolling the results of Schirmer’s test did not satisfy the diagnos- mill for different sizes and stand-seating manufacture. Roll- tic criteria for Sjögren’s syndrome, with the right eye ing is a plastic process in which the cross-sectional thick- showing a result of 12 mm in 5 min and the left eye ness of a material is reduced by successively pressing while showing a result of 7 mm in 5 min, they were found to passing it between two rollers. A roughing mill is the first be lower than the normal range. Other diseases such as process where slabs coming out of the furnace are rolled, hepatitis C, acquired immunodeficiency syndrome, and this produces dust containing silica.