iron pneumoconiosis
Introduction
Iron Pneumoconiosis Siderosis or iron pneumoconiosis is a long-term inhalation of metal dust or iron oxide dust caused by dust deposition in the lungs and mild proliferative lung disease of the fibrous tissue. In the past, iron oxide dust was considered to be "inert dust". Pulmonary fibrosis has been shown to cause mild connective tissue hyperplasia in lung tissue, so it has been suggested that iron pneumoconiosis is more appropriate. Iron dust has mild pulmonary fibrosis, which may be related to iron dust damage to alveolar macrophage membrane. basic knowledge The proportion of illness: 0.003%--0.005% Susceptible people: no specific population Mode of infection: non-infectious Complications: emphysema
Cause
Iron pneumoconiosis
Iron oxide dust (30%):
The fibrotic ability of iron oxide dust has been controversial. The focus is on whether iron oxide dust alone causes pulmonary fibrosis. In the early 1930s, it was found that the X-rays of the lungs of workers who have been engaged in welding for a long time have speckled shadows. The autopsy proved to be pure iron dust and no pulmonary fibrosis. Later studies showed that electric welding fume (the main component is iron oxide) can cause pneumoconiosis caused by pulmonary fibrosis. Experiments prove that alveolar macrophage damage plays an important role in the pathogenesis of pneumoconiosis. Role, and iron oxide dust can damage macrophage lysosomes to increase the content of lysosomal enzymes in the culture solution. The in vitro study showed that the alveolar giant was under the action of pure iron oxide dust with a concentration of 0.2-1.6 mg/ml. The survival rate of phagocytes was significantly reduced, indicating that the iron oxide dust had a damaging effect on the membrane. In animal experiments, the author also proved that 100 mg/iron oxide dust was injected into the trachea of rats, and collagen appeared at the edge of the lung dust chamber after 9 months. Fiber proliferation, the author also found from the three shipyard derusting autopsy materials found in the lungs have most of the dusty lesions (dust spots and nodules), pulmonary interstitial mild dust fibrosis, in summary iron dust Mild pulmonary fibrosis may be associated with iron dust damage to alveolar macrophage membranes.
pathology:
The performance is similar to that of the electric welder's pneumoconiosis, but the degree of lesion is much milder than that of the electric welder's pneumoconiosis. It is mainly characterized by the accumulation of a large amount of iron dust and dusty macrophages in the bronchioloalal alveolar, with dust spots, nodules and mild interstitial lung. Fibrosis, eye view, dark rust or dark rust-colored dust on the lung pleura, cut surface, dust stove (dust spots, nodules) scattered, about 1 mm in size, soft, often located next to the dilated bronchi. Especially the subpleural lesions are more obvious. They are in the form of strips or wedges that cling to the pleura and move along with the interlobular septa. Microscopically, the peripheral bronchiectasis is deformed, and the wall and its alveoli and the accompanying small blood vessels are surrounded. There is obvious iron dust, forming dusty lesions (dust spots or nodules), irregular dust spots, composed of dust cells, few or no collagen fibers, obvious peri-embolic emphysema, and generally nodules. Larger than the dust spots, it is star-shaped, there are more collagen fibers in the stove, and the lung interstitial has mild diffuse fibrous tissue hyperplasia.
Bronchopulmonary lymph nodes have a lot of iron dust, but lymph node tissue proliferation and structural damage are rarely seen.
Prevention
Iron pneumoconiosis prevention
The key to controlling and reducing silicosis lies in prevention. Prevention is first of all to reduce the dust of the working environment, strengthen publicity and education, formulate a health cleaning system, and achieve civilized production. Pre-employment and regular physical examinations, regular chest radiographs, and regular follow-up for those who have been out of dust. For those with upper respiratory tract disease, bronchopulmonary disease, especially those with tuberculosis and cardiovascular disease, they should not engage in dusting operations. Strengthen personal protection, pay attention to personal hygiene, carry out physical exercise, pay attention to nutrition and so on.
Complication
Iron pneumoconiosis Complications emphysema
Combined emphysema, combined with infection is common.
Symptom
Iron pneumoconiosis symptoms common symptoms chest tightness chest pain lung infection shortness of breath
Iron pneumoconiosis develops slowly and has a long course of disease. The symptoms are mild and mild in the early stage of the disease. Cough, cough, chest pain, chest tightness and shortness of breath may occur as the disease progresses. Symptoms and signs increase when the lung infection is combined.
Examine
Iron pneumoconiosis
In the early stage of X-ray examination, irregular small shadows were mainly used, and there were many lower lung fields in the two lungs. The rounded small shadows were rare and appeared very late. Generally, blocky large shadows rarely appeared, and pulmonary function tests showed ventilatory damage. The performance was reduced in lung capacity, and the maximum ventilation volume was reduced in the first second time and the maximum ventilation.
Increased white blood cells in patients with bacterial infection.
Chest X-ray performance can be divided into three phases.
1. In the early stage of morphological change: there are irregular shadows with high density and circular shadows with low density in the lung field.
2. Spotting period: Both lungs are covered with 2~4mm high density, sharp edge-like shadows on the edges, high density of hilar shadows, and similar to metal block shadows.
3. The formation of hilar metal block shadows: There are various forms around the first stage of the hilar, and the blocky shadows with high density along the bronchus are the deposition of tin in the bronchi and lung lymph nodes. Pulmonary function tests mainly showed that the maximum ventilation and the first second time were significantly lower than normal.
Diagnosis
Iron pneumoconiosis diagnosis
According to the history of dust exposure, X-ray findings and clinical symptoms, it is generally not difficult to make a diagnosis of stagnation (or pneumoconiosis), but China has not classified sputum as an occupational disease.
Differential diagnosis
1. Acute miliary tuberculosis: no occupational exposure history, more common in children. It is part of acute hematogenous disseminated tuberculosis, with acute onset, severe poisoning symptoms, sometimes associated with tuberculous meningitis and tuberculosis in other areas. X-ray chest radiograph shows uniform distribution of double lung fields, uniform density and size, edge Clear miliary shadows, anti-tuberculosis treatment is better. The clinical manifestations of silicosis have no symptoms of systemic poisoning, and the small nodule shadow has a higher density on the chest radiograph and a history of occupational exposure.
2. Hemosiderin: more common in rheumatic heart disease mitral stenosis, a history of left heart failure, no occupational history. It is characterized by repeated episodes of hemoptysis, shortness of breath and unexplained ischemic anemia. It has signs such as clubbing (toe) and spleen. Chest radiographs can be seen in varying sizes, uneven distribution, a certain number of fine nodule shadows, high density, with a small number of cord-like shadows, and extensive pulmonary interstitial fibrosis in the late stage. Macrophages that phagocytose hemosiderin can be found in sputum and bronchoalveolar lavage fluids, often with signs of heart disease.
3. Sarcoidosis: a granulomatous disease of unexplained, non-caseous epithelial cells. Can invade many organs of the body, but mostly in the lungs and intrathoracic lymph nodes. There were no obvious symptoms or signs in the early stage. The stage II nodular disease had hilar lymphadenopathy with pulmonary infiltration. The lung lesions were widely distributed symmetrically on both sides, showing nodular, punctate or flocculent shadows. Stage III sarcoidosis showed fibrotic changes in the lungs, while hilar lymph nodes disappeared. There are often granuloma shadows in the fibrotic shadows. In a wide range of lesions, lung shrinkage, diaphragmatic elevation, and hilar elevation may occur. The diagnosis of sarcoidosis is mainly based on chest radiograph, chest CT changes, histological biopsy and Kvein test. Patients may be accompanied by other organ lesions, serum angiotensin-converting enzyme activity is increased, tuberculin skin test negative or weak positive can be used as a reference indicator.
4. Alveolar microlithiasis: There is often a family history, and there is no history of dust exposure. X-ray chest radiographs are covered with fine sand-like shadows, the size is about 1mm, the edge is clear, the lungs are more common inside, the lungs are not big, the lung texture has no obvious changes, and the disease progresses slowly.
5. Bronchioloalveolar carcinoma: often cough more white foam sputum, sometimes hemoptysis, see cancer cells in the sputum.
